Category: Inter 1st Year

Andhra Pradesh BIEAP AP Inter 1st Year Botany Study Material 5th Lesson Morphology of Flowering Plants Textbook Questions and Answers.

AP Inter 1st Year Botany Study Material 5th Lesson Morphology of Flowering Plants

Very Short Answer Questions

Question 1.
Differentiate fibrous roots from adventitious roots. [T.S. May, 18]
Answer:

Question 2.
Define modification. Mention how root is modified in Banyan tree and mangrove plants.
Answer:
Modification is defined as “A permanent morphological change in an organ in order to perform a special function”. In banyan tree, roots develop from the huge branches and grow into the soil become pillar like called prop roots or piller roots. In Mangroves – Many roots come out of the ground, grow vertically upwards called Pneumatophores, or Respiratory roots help in gaseous exchange.

Question 3.
What types of specialized roots are found in Epiphytic plants? What is their function?
Answer:
In Epiphytic plants, velamen roots are present. They help in absorption of moisutrefrom atmosphere.

Question 4.
How does the sucker of chrysanthemum differ from the stolon of Jasmine?
Answer:

Question 5.
What is meant by pulvinus leaf base? In members of which angiospermic family do you find them? [A.P. May, 18, 17. Mar, 14]
Answer:
The swollen leaf base is called pulvinous leaf base. It is seen is “Leguminasae” family.

Question 6.
Define venation. How do Dicots differ from Monocots with respect to venation. [A.P. Mar, 15]
Answer:
“The arrangement of veins and the veinlets in the lamina of the leaf” is called venation.

In Dicots, Midrib, lateral veins and veinlets form a network so called Reticulate venation.

In Monocots, the veins run parallel to each other within a lamina so called parallel venation.

Question 7.
How is Pinnately compound leaf is different from a palmately compound leaf? Explain with one example each.
Answer:
Lamina is divided into leaflets which are arranged on either side of the rachis is called pinnately compound leaf.
Ex : Neem

Lamina is divided into leaflets, which are arranged at the tip of the petiole, called Palmately compound leaf.
Ex : Bean, Citrus.

Question 8.
Which organ is modified to trap insects in Insectivorous plants? Give two examples. [Mar, 13]
Answer:
In Insectivorous plants, leaves (Lamina) are modified to trap insects.
Ex : Nepenthes, Drosera.

Question 9.
Differentiate between Racemose and Cymose inflorescences. [T.S. Mar, 15]
Answer:

Question 10.
What is the morphology of cup like structure in Cyathium? In which family it is found?
Answer:
In Cyathium, cup like structure is formed from Involucre of Bracts. It is seen in “Euphorbiaceae” family.

Question 11.
What type of Inflorescence is found in fig trees ? Why does the insect Balstophaga visits the Inflorescence of fig tree?
Answer:
In ‘Fig’ trees, ‘Hypanthodium’ Inflorescence is seen. An Insect called ‘Blastophaga’ visits this inflorescence, because it lay its eggs in the gall flowers.

Question 12.
Differentiate actinomorphic from zygomorphic flower.
Answer:

Question 13.
How do the petals in pea plant are arranged? What is such type of arrangement called?
Answer:
In Pea and Bean Flowers, there are five petals. The largest petal (standard) overlaps the two lateral petals (wings) which in turn overlap the two smallest anterior petals (Keel). This type of aestivation is called Descendingly Imbricate aestivation. This type of corolla is called vexillary or papilionaceous corolla.

Question 14.
What is meant by eipetalous condition? Give an example.
Answer:
When the stamens are attached to the petals that condition is called Epipetalous condition.
Ex : Brinjal, Datura.

Question 15.
Differentiate between apocarpous and syncarpores ovary.
Answer:

Question 16.
Define placentation. What type of placentation is found in Dianthus. [T.S. Mar, 15]
Answer:
“The arrangement of ovules with in the ovary is known as placentation”. In Dianthus – Free Central placentation is seen.

Question 17.
What is meant by parthenocarpic fruit? How is it useful?
Answer:
The fruit which is formed without fertilization of the ovary is called parthenocarpic fruit. They are useful commercial production of seedless fruits and also useful in Juice Indus tries.

Question 18.
What is the type of fruit found in mango ? How does it differ from that of coconut?
Answer:
In Mango, the type of fruit is Drupe. In Mango Epicarp is thin, Mesocarp is fleshy and edible and endocarp is stony. Where as in coconut, the mesocarp is fibrous.

Question 19.
Why certain fruits are called false fruits? Name two examples of plants having false fruits. [T.S. May, 18. Mar, 13]
Answer:
Fruits which are formed form other parts of the flower along with ovary are called false fruits.
Ex : Apple – Thalamus develops into false fruit.
Cashewnut – Pedicel develops into False fruit,

Question 20.
Name any two plants having single seeded dry fruits.
Answer:
(1) Rice (Caryopsis) (2) Cashew nut (nut) (3) Tridax (Cypsela)

Question 21.
Define Schizocarpic dry fruits. Give an example.
Answer:
The fruits which split into one-seeded bits, called mericarps and are called Schizocarpic fruits.
Ex : Acacia, Castor. ,

Question 22.
Define mericarp. In which plant you find it?
Answer:
The one seeded bits of Schizocarpic fruits are called mericarps.
Ex : Acacia.

Question 23.
What are aggregate fruits? Give two examples. [A.P. May, 18]
Answer:
In custard apple. Many carpels are present. Each carpel of apocarpous gynoecium develops into a fruitlet. Such bunch of fruitlets are called aggregate fruits.
Ex : Annona, Naravalia.

Question 24.
Name a plant that has single fruit developing from the entire inflorescence. What is such a fruit called? [Mar, 14]
Answer:
Pine apple. This fruit is called composite fruit.

Short Answer Type Questions

Question 1.
Explain different regions of root with neat labelled diagram.
Answer:

The tip of the root is covered by Thimble like structure called root cap which protect the root apex. A few m.m above the root cap, meristematic zone is present which consists of small, thin walled cells with dense protoplasm. These cells divide repeatedly. The cells proximal to this zone undergo rapid elongation and enlargement and are responsible for growth of the root in length.

This region is called elongation region. The cells of the elongation zone gradually differentiate and mature so called maturation zone. From this zone, some of the epidermal cells form very thin and delicate thread like structures, called root hairs which help in absorption of water and Minerals from the soil.

Question 2.
Justify the statement, “Underground parts of plants are not always roots”.
Answer:
In some plants, stems are underground and help in storage of food materials, organs of perennation to tide over unfavourable conditions, vegetative propagation and also protect themselves form grazing animals. More over, underground stems bear nodes, internodes, buds and scale leaves. Because of this, they are treated as stems but not roots, so underground parts of plants are not root.
Ex : Stem tuber of Potato, Rhizome of Zinger, Turmeric, corm of Amorphophallus, Colocasia and Bulb of onion.

Question 3.
Explain with examples different types of phyllotaxy.
Answer:
Arrangement of leaves on the stem or on the branchs is called Phyllotaxy. It is of three types.
A) Alternate Phyllotaxy : A single leaf arises at each node arranged in alternate manner.
Ex : Hibiscus rosa-sinensis, mustard.

B) Opposite Phyllotaxy : A pair of leaves arise at each node and lie opposite to each other.
Ex : Calotropis, Guava.

C) Whorled Phyllotaxy : More than two leaves arise at a node and form a whorl.
Ex : Nerium, Alstonia.

Question 4.
How do leaf modifications help plants?
Answer:
Leaf modifications will help to plants in Many ways. They are
a) In weak stemmed plants like peas, leaves are converted into long, coiled tendrils and help in climbing.
b) In Desert plants like Cacti, leaves are modified into spines, which gave protection from grazing animals.
c) In Onion and Garlic : The fleshy leaves help in storage of food materials.
d) In Australian acacia, the leaves are pinnately compound in which leaflets are small and short lived. The petioles of these plants expand, become green and synthesize food called phyllodes.
e) In Insectivores plants, like Nepenthes, Dionea, leaves are modified into traps which kill insects for their nitrogen requirement.
f) In Bryophyllum, epiphyllous buds which arise from the notches of the leaves develop into new plants, thus help in vegetative Propagation.

Question 5.
Describe any two special types of Inflorescences.
Answer:
1) Cyathium :

It is a single flower like special inflorescence found in Euphorbiaceae members. The inflorescence is covered by a deep cup like involucre of bracts. At the centre of the cup, there is a single female flower represented by a long stalked tricarpellary, Syncarpous pistil. Encircling this females flower, many male flowers are arranged in scorpioid cymes. Each male flower is represented by a single and stalked stamen. Male and female flowers are achlymadeous. Flowers are arranged in centrifugal manner.
Ex : Euphorbia and Poinsettia

2) Hypanthodium :

It is a fruit like inflorescence. The inflorescence axis is condensed and forms a fleshy, cup like structure with an apical opening. Small, sessile, unisexual flowers develop on the inner wall of the cup. Male flowers are near the apical opening and female flowers are at the base. In between these two types of flowers, some sterile female flowers called ‘gall flowers’ are present. The opening of flowers is not in a definite order.
Ex : Ficus species.

Question 6.
Describe the arrangement of floral membes in relation to their insertion on thalamus.
Answer:
Based on the position of Calyx, corolla and androecium on thalamus in respect to the ovary, the flowers are of three types.
They are :
A) Hypogynous,
B) Perigynous,
C) Epigynous

A) Hypogynous flower :
The gynoecium occupies the highest position, while the other parts are situated below it. The ovary is said to be superior.
Ex : Mustard, Brinjal.

B) Perigynous flower :
Gynoecium is present in the centre of the thalamus and other parts of the flower are located on the rim of the thalamus. The ovary is said to be half superior.
Ex : Rose, Pea.

C) Epigynous flower :
The ovary is completely embeded in the cup like thalamus. Other floral parts of the flower arise just above the ovary. In this, the ovary is said to be Inferior.
Ex : Guava, Cucumber.

Question 7.
“The flower of many angiospermic plants which show sepals and petals differe with respect to the arrangement of sepals and petals in respective whorls” – Explain.
Answer:
The mode of arrangement of sepals or petals in floral bud is knwon as Aestivation. It is of 4 types.
A) Valvate :
“When sepals or petals in a whorl just touch one another at the margins without overlapping”.
Ex : Calotropis.

B) Twisted :
“If the margin of the appendage overlaps that of the next one and so on”.
Ex : Cotton, Hibiscus. (Petals).

C) Imbricate :
If the margins of sepals or petals overlap one another but not in any particular direction.
Ex : Cassia, gulmohar.

D) Vexillary :
5 petals are present, of which the largest Petal (standard) overlaps the two lateral petals (Wings) which in turn overlap the two smallest anterior petals (keel). This is known as vexillary or papilionaceous aestivation.
Ex : Pea, Bean.

Question 8.
Describe any four types of placentations found in flowering plants.
Answer:
The arrangement of ovules with in the ovary is known as placentation. It is of 5 types.
A) Marginal :
“The placenta forms a ridge along the ventral suture of the ovary and the ovules are borne on this ridge forming two rows”.
Ex : Pea.

B) Axial :
The ovules are attached to central placenta in a multilocular ovary.
Ex : Tomato, lemon.

C) Parietal :
The ovules develop on the inner wall of the oary. Ovary is one chambered but it becomes two chambered due to the development of flase septum.
Ex : Mustard.

D) Free central :
The ovules are borne on central axis without septa.
Ex : Dianthus.

E) Basal :
The placenta develops at the base of the ovary and a single ovule is attached to it.
Ex : Sunflower.

Question 9.
Describe in brief fleshy fruits you studied.
Answer:
Fruits which become fleshy at maturity one are called fleshy fruits. They are 5 types.
1) Berry :
It develops from Bi or multicarpellary syncarpous Gynoecium. The mesocarp and endocarp are fused to form the pulp and the seeds are hard.
Ex : Tomato, Guava.

2) Pepo :
It develops from Tricarpellary syncarpous inferior ovary. The epicarp is rigid, the mesocarp is fleshy and the endocarp is smooth.
Ex : Cucumber.

3) Pome :
It develops from Bi of multicarpellary inferior ovary and is surrounded by fleshy thalamus. The endocarp is cartilegumous.
Ex : Apple.

4) Hesperidium :
It develops from Multicarpellary syncarpous, superior ovary. The epicarp is leathery with volatile giands, Mesocarp is papery and endocarp is several chambered with juicy hairs.
Ex : Citrus.

5) Drupe :
It develops from Monocarpellary superior ovary. In Mango, the epicarp is thin, a middle fleshy edible mesocarp and inner stony hard endocarp. In coconut, the mesocarp is fibrous.

Question 10.
Describe with examples, the various dry fruits you studied.
Answer:
The fruits which become dry at maturity are called Dry fruits. They are of 3 types.
1) Dry dehiscent fruits :
“The fruits which breaks and liberate the seeds”.
Ex : (a) In legumes the fruit dehisces dorsiventrally into two halves and liberate the seeds,
(b) In Cotton, Datura – The capsule dehisce in different ways to liberate the seeds.

2) Dry Indehiscent fruits :
The fruits do not break and liberate the seeds only after the disintegration of pericarp.
Ex : (a) In Rice, The fruit is caryopsis. In this the pericarp and seed coat fuse together.
(b) In Cashew, the fruit is nut, whiph develops from multicarpellary, Syncarpous ovary. The pericarp is stony.
(c) In Tridax, The fruit is cypsela, Identified by the presence of persistent pappus like calyx.

3) Schizocarpic fruits :
“The fruit at maturity split into one – seeded bits called mericarps”.

Long Answer Type Questions

Question 1.
Define root. Mention the types of root systems. Explain how root is modified to perform different functions. [A.P & T.S. Mar, 17, 15, 13]
Answer:
The Radicle of the embryo elongates leads to the formation of primary root which grows into the soil is called root. In Angiosperms, two types of root systems are present namely, (a) Tap root system (b) Fibrous root system.

a) Tap root system :
The primary root grows into the soil called tap root, which produce lateral roots and root lets constitutes tap root system. It is seen in Dicotyledonous plants.

b) Fibrous root system :
The primary root is short lived and is replaced by a large number of roots which orginate from the base of the stem constitutes fibrous root system. It is seen in Monocotyledonous plants.

Root Modifications :
In some plants, roots change their shape and structure to perform functions other than absorption and conduction of water and Minerals called root modifications. They are of different types.

1) Storage roots :
In Carrot, turnip (Tap roots), Sweat potato (Adventitious roots), Asparagus (Fibrous roots) become swollen due to storage of food called storage roots.

2) Prop roots :
In Banyan tree, Roots arise from the branches grow into the soil, become pillar like and give additional support called prop roots or pillar roots.

3) Stilt oots :
In Maize, sugarcane, roots arise from the lower nodes of the stem, give additional support called stilt roots.

4) Respiratorty roots :
In Mangroves like Rhizophora and Avicennia, Many roots come out of the ground and grow vertically upwards, help in respiration called Pneumatophores.

5) Epiphytic roots :
In Epiphytes like Vanda, special adventitious roots arise, help in absorption of moisture from almosphere called Velamen roots.

6) Parasitic roots :
In partial parasites like viscum and strga, some Haustorial roots enter into xylem of the host plant to get water and Minerals. In complete parasitic like cuscuta and Rafflesia, the haustorial roots enter into xylem and phloem of the host plant and obtain water and Minerals and food materials called Parasitic roots.

7) Nodular roots :
In the members of Fabaceae, the roots are inhabited by Rhizobium bacteria which helps in N2 fixation called Nodular roots.

8) Photosynthetic roots :
In some plants like Taeniophyllum, the roots are chlorophyllous and perform photosynthesis so called photosynthetic roots.

Question 2.
Explain how stem is modified variously to perform different functions. [Mar, 14] [A.P & T.S. Mar, 18]
Answer:
Stems are modified in several ways to perform different functions.

In some plants stem grows into soil, not only stores food materials but also acts as organs of pennations. Such stems are called underground stem modifications. Further, they also help in vegetative propagation.
Ex : The stem tuber of potato, Rhizome of zingiber, corm of colocasia and Bulb of onion.

In some plants, Aerial stems show many modifications.
1) Tendrils :
Slender, spirally coiled structures which may develop either from Auxiliary Bud [Cucumber, watermelon] or from Terminal Bud [Grapes] called stem Tendrils, help in climbing.

2) Thorns :
In some plants, buds are modified into woody, straight, pointed thorns, which protect plants from grazing animals.
Ex : Citrus, Bougainvillaea.

3) Phylloclade :
In some plants of arid regions, stems are modified into fleshy flattened (opuntia) or fleshy cylindrical (Euphorbia) or needle like structures (casuarina), called phylloclades. They carry out photosynthesis as their leaves are reduced to scales or spines to reduce the transpiration.

4) Bulbils :
In some plants, the vegetative buds (Diascorea) or floral buds (Agave) store food materials. At maturity they detach from the parent plants, develop adventitious roots and help in vegetative propagation. These are called Bulbils.

In some plants, some part of the stem is aerial and some part is underground. Such stems are called sub aerial stem modifications.
1. Runners :
Sub aerial stems of “oxalis” spread to new niches and form new plants when older parts die. Such plants are called runners.

2. Stolons :
In plants like Nerium, Jasmine, a slender lateral branch called ‘stolon’ arises from the base of the main axis, grow vertically, arches downwards and touch the ground, produce adventitious roots.

3. Off-sets :
In some aquatic plants like pistia and Eichhornia, a lateral branch of one internode length called offset which bears a rosette of leaves at each node and a tuft of adventitious roots arising from the base of the discoid stem.

4. Suckers :
In plants like banana, chrysanthemum, the lateral branches originate from the basal portion of the main stem, grows horizontally, beneath the soil and then come out obliquely upwards giving rise to leafy shoots. These branches are called suckers. All these sub-aerial stem modifications help in vegetative propagation.

Question 3.
Explain different types of Racemos inflorescences.
Answer:
Racemose Inflorescences are of several types. They are :
1) Simple Raceme :
The pedunde is simple, unbranched producing many pedicellate, bracteate flowers in Acropetal Manner.

2) Corymb :
The peduncle is long, and bears many flowers in Acropetal manner, but all the flowers are brought to the same level due to varied lengths of pedicels even through they are borne at different nodes.
Ex : Cassia, Cauliflower.

3) Umbel :
The flower appear to have arisen from the same point of the peduncle and is called umbel type. The Inflorescence is covered by a whorl of bracts called “Involucre”. Ex : Apiaceae, carrot.

4) Spike :
The peduncle is long and bears many sessile flowers, arranged in Aeropetal Manner.
Ex : Achy rant hus, poaceae.

5) Spadix :
In some plants, penduncle bears sessile unisexual and neutral flowers arranged in acropetal manner, covered and protected by modified Bract called spathe.
Ex : Cocos, colocasia.

6) Head :
In some plants, unisexual and bisexual sessile flowers develop centripetially on a condensed peduncle.
Ex : Tridax, sunflower.

Additional Questions & Answers

Question 1.
What is meant by Scutellum? In which type of seeds it is present?
Answer:
Large and shield shaped cotyledon is known as scutllum. It is seen in Monocot seeds.

Question 2.
Define with examples endospermic and non-endospermic seeds.
Answer:
Endosperm may be completely consumed by the developing.

embryo before seed maturation. Such seeds are called non-endospermic seeds.

The seeds with endosperm after maturation are called endospermic seeds.
Ex : Castor, Coconut.

Intext Questions

Question 1.
In which plant, the underground stem grows horizontally in soil and helps in perennation?
Answer:
Zingiber officinalis (ginger) – Rhizome.
Curcuma tonga (Turmeric) – Rhizome.

Question 2.
Needle like phylloclades are found in which plant?
Answer:
Casuarina.

Question 3.
Why do plants like Nepenthes trap Insects?
Answer:
Nepenthes generally grow in Nitrogen deficient soils. In this, leaves are modified into pitcher to trap insects for their nitrogen requirement.

Question 4.
What is the characteristic Inflorescence found in members of Asteraceae?
Answer:
Head or Capitulum.

Question 5.
Can you name a plant that has least number of flowers in its inflorescence?
Answer:
Hibiscus, Datura.

Question 6.
Which family shows naked flowers?
Answer:
Euphorbiaceae.

Question 7.
In which flowers of the fig trees does the Insect Blastophaga lay its eggs ?
Answer:
Gall flowers.

Question 8.
What type of symmetry is shown by the flowers of Canna?
Answer:
Asymmetric.

Question 9.
On which side of the flower do the flowers of pea have the keel petals?
Answer:
Anterior side.

Question 10.
What is the ratio of overlapping margins of petals to overlapped ones in imbricate aestivation?
Answer:
5 : 4

Question 11.
How many ovules are found attached in Basal placentation?
Answer:
One

Question 12.
Which part of the flower in Cashew plant forms the false fruit?
Answer:
Pedicel

Question 13.
Which plant has hard, stony endocarp and fleshy edible mesocarp?
Answer:
Mango

Question 14.
What is the morphology of spathe in spadix Inflorescence?
Answer:
Bract (enlarged)

Question 15.
What is the type of fruit known as if it develops from apocarpus ovary of a single flower?
Answer:
Aggregate fruits. (Anona squamosa)

Andhra Pradesh BIEAP AP Inter 1st Year Botany Study Material 4th Lesson Plant Kingdom Textbook Questions and Answers.

AP Inter 1st Year Botany Study Material 4th Lesson Plant Kingdom

Very Short Answer Questions

Question 1.
What is the basis of classification of Algae?
Answer:
The basis for the classification of Algae is pigmentation and the type of stored food.

Question 2.
When and where does reduction division take place in the life cycle of a liverwort, a moss, a fern, a gymnosperm, and an angiosperm?
Answer:
In liver worts, reduction division occurs in sporophyte as a result spores are produced in the capsule.

In Mpsses, reduction division occurs in sporophyte in spore mother cells.

In ferns :
Reduction division occurs in Macro and Micro sporangia to produce Macrospores and Microspores.

In Gymnosperms – Reduction division occurs in Microsporangia and Megasporangia.

In Angiosperms – Reduction division occurs in Microspore Mother cells (Anther), Megaspore Mother cell (ovule).

Question 3.
Differentiate between syngamy and triple fusion.
Answer:

Question 4.
Differentiate between antheridium and archegonium.
Answer:

Question 5.
What are the two stages found in the gametophyte of mosses? Mention the structure from which these two stages develop?
Answer:
The gametophyte of Mosses consists of two stages namely
a) Juvenile stage, the Protonema and
b) Adult leafy stage, gametophore.

Protonema is developed directly from spore. Gametophore is developed from the protonema as a lateral adventitious bud.

Question 6.
Name the stored food materials found in Phaeophyceae and Rhodophyceae.
Answer:
In Phaeophyceae, the stored food material is Laminarin or Mannitol. The stored food material in Rhodophyceae is floridean starch.

Question 7.
Name the pigments responsible for brown colour of phaeophyceae and red colour of Rhodophyceae.
Answer:
“Fucoxanthin” pigment is responsible for brown colour of phaeophyceae and “r-phycoerythrin” is responsible for red colour of Rhodophyceae.

Question 8.
Name different methods of vegetative reproduction in Bryophytes. [A.P. Mar. 15]
Answer:
In Bryophytes vegetative Reproduction takes place by fragmentation or by Gemmae, or by budding in secondary protonema.

Question 9.
Name the integumehted megasporangium found in Gymnosperms. How many femals gametophytes are generally formed inside the megasporangium?
Answer:
The Integumented Megasporangium found in Gymnosperms is ovule. One multicellular female gametophyte develops inside the megasporangium which bears two or more archegonia.

Question 10.
Name the Gymnosperms which contain mycorrhiza and coralloid roots respectively.
Answer:
The Gynnosperm which contain Mycorrhiza is pinus, and which contain corralloid roots is cycas.

Question 11.
Mention the ploidy of any four of the following.
a. Protonemal cell of a moss.
b. Primary endosperm nucleus in a dicot.
c. Leaf cell of a moss.
d. Prothallus of a fern,
e. Gemma cell in Marchantia
f. Meristem cell of monocot
g. Ovum of a liverwort and
h. Zygote of a fern.
Answer:
a) Haploid
b) Triploid
c) Haploid
d) Haploid
e) Haploid
f) Diploid
g) Haploid
h) Diploid

Question 12.
Name the four classes of pteridophyta with one example each.
Answer:
The four classes of pteridophyta are :
i) Psilopsida Ex : Psilotum
ii) Lycopsida Ex : Lycopodium
iii) Sphenopsida Ex : Equisetum
iv) Pteropsida Ex : Pteris

Question 13.
What are the first organisms to colonise rocks? Give the generic name of the moss which provides peat?
Answer:
The first organisms to colonise rocks are Mosses along with Lichens. Generic name is sphagnum.

Question 14.
Mention the fern characters found in Cycas.
Answer:
Some of the fern characters are :

1. Circinate vernation of young leaves.
2. Presence of ramenta.
3. Multiciliated Male gametes.
4. Presence of Archegonia.

Question 15.
Why are Bryophytes called the amphibians of the plant Kingdom?
Answer:
They live in moist soil and they depend on water for sexual reproduction. So they are called amphibians of plant Kingdom.

Question 16.
Name an algae which show
a) Haplo – diplontic and b) Diplontic types of life cycles.
Algae which show Haplo – diplontic life cycle is Ectocarpus. Algae that show Diplontic life cycle is Fucus.

Question 17.
Give examples for unicellular, colonial and filamentous algae.
Example are volvox, spirogyra and chara. These are the members of chlorophyceae.

Short Answer Type Questions

Question 1.
Differentiate between red algae and brown algae. [A.P. May. 18, Mar. 14]
Answer:

Question 2.
Differentiate between liverworts and mosses.
Answer:

Question 3.
What is meant by Homosporous and Heterosporous pteridaphytes? Give two examples. [T.S. May. 18 A.P. Mar. 18, 15, 13]
Answer:
Pteridophytes which produce similar type of spores are called Homosporous pteridophytes.
Ex : Lycopodium, Pteris.

Pteridophytes which produce two types of spores are called Heterosporous Pteriodophytes.
Ex : Selaginella, Saivinia.

Question 4.
What is Heterospory? Briefly comment on its significance. Give two examples. [T.S. Mar, 15]
Answer:
Heterospory refers to the production of different types of spores.

Significance :

1. Microspores formed from Microspore mother cells are small with 0.015 – 0.05 mp. Megaspores formed from Megaspore Mother cell are big and are with 1.5 mp.
2. Microspores develop into Male gametophytes and Megaspores develop into female gametophytes which lead to unisexuality.
3. The female gametophytes are retained on the parent sporophyte for variable periods.
4. The development of zygote into young embryos takes place within the female gametophytes.
5. The female gametophyte is with abundant food materials.
   Ex : Selagenella, Saivinia.

Question 5.
Write a note on economic importance of Algae and Bryophytes.
Answer:
Importance of Algae :

1. At least a half of the carbon dioxide fixation on earth is carried out by Algae through photosynthesis and increases the level of oxygen in the environment.
2. They are paramount importance as primary producers of energy rich compounds which form the basis of the food cycles of aquatic animals.
3. Many species of Porphyra, Laminaria and sargassum are used as food.
4. Some marine Brown and red algae produce large amounts of hydro carbons.
   Ex : A/gin and Carrageen.
5. Iodine is extracted from kelps like Laminaria.
6. Chlorella and Spirullina are used as food supplements even by space travellers.

Economic importance of Bryophytes :

1. Some mosses provide food for herbaceous mammals, birds and other animals.
2. Species of Sphagnum, a moss provide peat used as fuel and because of its capacity to hold water as packing material for trans – shipment of living material.
3. Mosses along with lichens are the first organisms to Colonise rocks.
4. They play significant role in plant succession.
5. Mosses form dense mats on the soil, thus they reduce the impact of falling rain and prevent soil erosion.

Question 6.
How would you distinguish Monocots from Dicots.
Answer:

Question 7.
Give a brief account of Prothallus.
Answer:
In Pteridophytes, the spores germinate to give rise to Inconspicuous, small but multicellular free living, photosynthetic thalloid gametophytes called Prothalli. They require cool, damp, shady places to grow. Because of this specific requirement and water for fertilization, the spread of living pteridophytes is limited and restricted to narrow geographical regions. The gametophytes bear male and female sex organs, called antheridia and archegonia respectively. The sex organs are multicellular, jacketed and sessile.

Question 8.
Draw labelled diagrams of :
a) Female thallus and Male thallus of a liverwort.
b) Gametophyte and sporophyte of funaria.
Answer:

Long Answer Type Questions

Question 1.
Name three groups of plants that bear archegonia. Briefly describe the life cycle of any one of them.
Answer:
Bryophytes, Pteridophytes and Gymnosperms are the three ‘groups of plants that bear archegonia. The plant body in bryophytes is haploid. It produces gametes hence it is called gametophyte. The sex organs are multicellular, Jacketed and stalked. Antheredium, which is the male sex organ produces biflagellate antherozoids. Archegonium, the female sex organ, which is flask shaped, produces a small egg.

The antherozoids are released into water where they come in contact with archegonium. One antherozoid fuses with the egg to produce the zygote. This is called zooidogamous oogamy. Zygote produce a multicellular body called sporophyte. It is attached to the photosynthetic gametophyte and extracts nourishment from it.

Some cells of the sporophyte, called spore mother cells undergo reduction division to produce Haploid spores. These spores germinate to produce gametophyte. Bryophytes show alternation of generations (because garhetophytic and sporophytic bodies are different) and life cycle is Haplo-diplontic type.

Question 2.
Describe the important characteristics of Gymnosperms.
Answer:

1. Gymnosperms are embryophytic, trachaeophytic, archegoniate phanerogams.
2. They include medium size trees or tall trees and shrubs.
3. The root system is tap root system. In some genera roots have fungal association in the form of mycorrhiza (Pinus) and in some Cycas roots have coralloid roots which are associated with Nitrogen fixing Cyanobacteria (Nostbc and Anabaena)
4. The stems are unbranched (Cycas) or branched (Pinus Cedrus).
5. The leaves may be simple or compound. In Cycas, the pinnate leaves persists for a years in Cycas.
6. Anatomically the stem shows eustele. The vascular bundles are conjoint, collateral and open.
7. Vessels are generally absent in xylem and companion cells are absent in phloem.
8. Secondary growth occurs in stem and roots.
9. The Gymnosperms are heterosporous, they produce haploid microspores and megaspores.
10. The two types of spores are produced in sporangia that are borne on sporophylls which are arranged spirally an aixs to form compact strobili.
11. The male strobili consists of microsporophylls and Microsporangia which produce Micro-spores.
12. Microspores or pollen grains develop into Male gametophyte.
13. The strobili bearing Megasporophylls with ovules are called female strobili.
14. Micro and Megasporphylls may be borne on the same tree (Pinus) or on different trees (Cycas).
15. Megaspore develop into female gametophyte. The pollination is direct and anemophilous.
16. Gymnosperms are divided into three classes namely Cycadopsida, Coniferopsida and Gnetopsida.

Question 3.
Give the sailent features of Pteridophytes.
Answer:

1. Pteridophytes are used for medicinal purposes and as soil-binders.
2. These are the first terrestrial plants to possess vascular tissues.
3. They are embryophytic, archegoniate vascular cryptogams.
4. They prefer cool, damp and shady places.
5. The plant body is a sporophyte which is differentiated into true roots, stem and leaves.
6. The root system is adventitious.
7. The stele may be protostele or siphonostele or solenostele or’dictyostele.
8. The leaves are small (selagenella) or large as in ferns.
9. The sporophytels bear sporangia that are subtended by leaf like sporophylls.
10. Most of the pteridophytes are homosporous but selaginella and Salvinia shows Heterosporous.
11. The spores germinate to give rise to Prothalli.
12. The gametophytes bear male and female sex organs called antheridia and archegonia.
13. The sex organs are multicellular, jacketed and sessile.
14. Fusion of Male gamete with the egg present in the archegonium results in the formation of zygote.
15. Zygote develops into young embryo which produces a multicellular sporophyte.

Question 4.
Give an account of plant life Cycles and alternation of Generations.
Answer:
In plant, both haploid and diploid cells can divide by mitosis which leads to the formation of different plant bodies, haploid and diploid. The haploid plant body produces gametes by mitosis and is called gametophyte. It is followed by fertilization, which results in the formation of zygote which also divides by mitosis to form diploid sporophytic plant body. In this, Meiosis occurs, results in the formation of spores. These spores again divide by mitosis to form a Haploid plant body. Thus during life cycle there is a alternation of generations between gamete producing haploid gametophyte and spore producing diploid sporophyte.

Different plants show different life cycles. For Ex :
1) Many Algae such as Vo/vox, Spirogyra and some species of Chlamydomomas shows Haplontic life cycle. In this, zygote represents the sporophytic stage which divides by meiosis results in the formation of Haploid spores. These spores divide mitotically and form the gametophyte.

2) In some species, the diploid sporophyte is the dominant photosynthetic. Independent phase of the paint. The haploid phase is represented by gametes only. So this lifecycle is called diplontic type. In some pteridophytes, the gametophyte is represented by few celled stage so called diplo-haplontic type. Other exmples are polysiphonia.

3) In Bryophytes, both phases are multicellular with dominant gametophytic phases and dependent sporophytic phage. So this life cycle is called haplo-diplontic type. Other examples for this are Ectocarpus, Laminaria.

Question 5.
Both Gymnospoerms and Angiosperms bear seeds then why are they classified separately?
Answer:

Andhra Pradesh BIEAP AP Inter 1st Year Botany Study Material 3rd Lesson Science of Plants – Botany Textbook Questions and Answers.

AP Inter 1st Year Botany Study Material 3rd Lesson Science of Plants – Botany

Very Short Answer Questions

Question 1.
Explain how the term Botany has emerged.
Answer:
In the ancient Greek language, the term Bouskein means Cattle feed. The term ‘Bouskein’ gave rise to “Botane” from which the term “Botany’’ is derived.

Question 2.
Name the books written Parasara and mention the important aspects discussed in those books. [A.P. Mar. 17]
Answer:
Parasara’s ‘Krishi Parasaram’ mentioned about agriculture and weeds. ‘Vrikshayurveda’ gives information about 14 types of forests; the external and internal characters of plants and about medicinal plants.

Question 3.
Who is popularly known as father of Botany ? What was the book written by him? [T.S. Mar, 18]
Answer:
“Theophrastus” is regarded as the Father of Botany. The book written by him was ‘De Historia plantarum”,

Question 4.
Who are Herbalists? What are the books written by them?
Answer:
The scientists who described the live Medicinal plants technically are called the Herbalists. The books written by them are called Herbals.

Question 5.
What was the contribution of Carolus Von Linnaeus for the development of plant taxonomy?
Answer:
“Carolus Von Linnaeus” popularised Binomial Nomenclature. He also proposed the sexual system of classification.

Question 6.
Why is Mendel considered as the father of Genetics?
Answer:
Mendel conducted Hybridization experiments on pea plants and also introduced the laws of inheritance in 1866. Hence, he is considered as the Father of Genetics.

Question 7.
Who discovered the cell and what was the book written by him? [A.P. May 17, Mar 14]
Answer:
Robert Hooke first discovered the cell. “Micrographia” was the book written by him.

Question 8.
What is Palaeobotany? What is its use? [T.S. Mar, 17, 15, 13]
Answer:
Palaeobotany deals with the study of fossil plants. It helps in understanding the course of evolution in plants.

Question 9.
Name the branches of Botany which deal with the chlorophylfous autotrophic thallophytes and non-chlorophyllous heterotrophic thallophytes.
Answer:
Study of chlorophyllous autotrophic thallophytes is called Phycology. Study of non- chlorophyllous heterotrophic thallophytes is called Mycology.

Question 10.
What are the group of plants that live as symbionts in lichens? Name the study of Lichens. [T.S. May, 18]
Answer:
Algae and Fungi are the plant groups that live as symbionts in lichens. The study of lichens is called lichenology.

Question 11.
Which group of plants are called Vascular cryptogams ? Name the branch of Botany which deals with them?
Answer:
“Pteridophytes” are called vascular cryptogams. The branch of Botany that deals with them is called Pteridology.

Question 12.
Which group of plants are called amphibians of plant kingdom? Name the branch of Botany which deals with them.
Answer:
Bryophytes are called amphibians of plant Kingdom. The branch that deals with Bryophytes is called Bryology.

Short Answer Type Questions

Question 1.
Explain in brief the scope of Botany in relation to agriculture, horticulture and medicine.
Answer:

1. The problems like decreasing resources and increasing population could be solved by enhancing crop yield through Green Revolution and.also by developing disease* pest resistance crops by utilizing the principles of Biotechnology.
2. Progress in Agriculture, Forestry horticulture is possible through hybridization experiments and Genetic Engineering technology.
3. New plant breeding techniques are useful to develop hybrid varieties in crop plants like Rice, Wheat, Maize, Sugarcane etc.
4. Phytopathology is helpful in the prevention and eradication of several plant diseases.
5. Knowledge on the role of plant hormones in plant growth and development is significant to improve Agriculture and Horticulture through herbicidal control of weed, breaking of seed dormancy etc., Experiments in tissue and organ culture is possible to produce large number of plants in the laboratory within a short duration.
6. Several industries could be developed based on Botany.
7. Studies in Medicinal plants like Arnica, Cinchona, Neem, Datura, Rauwolfia, Ocimum are also important to explore them for human health care.
8. Production of Antibiotics, Bioinsecticides, single cell proteins is also made possible by study of these product yielding plants.

Question 2.
Explain the scope of Botany taking plant physiology as example.
Answer:

1. The role of Minerals iri plant nutrition is useful in rational usage of chemical fertilizers and control of mineral deficiencies to improve Agricultural productivity.
2. Knowledge on the role of plant hormones in plant growth and development’s highly significant to improve Agriculture and horticulture through herbicidal control of weeds, breaking of seed dormancy, enhancement of shelf-life period of leafy vegetables like spinach, artificial ripening of fruits like apple, banana and rooting of stem cuttings for Vegetative propogation.

Question 3.
What are the different branches of botany that deal with morphology of plants ? Give their salient features.
Answer:
Morphology deals with the study of different organs of a plant. It is a fundamental requisite for classification of plants. It is of two types,
a) External Morphology
b) Internal Morphology.

a) External Morphology :
It is the study and description of external characters of plant organs like root, stem, leaf, flower, seed and fruit etc.

b) Internal Morphology :
It is the study of internal structure of different plant organs. It is of two types. They are i) Histology ii) Anatomy.
i) Histology :
Study of different tissues present in the plant body.

ii) Anatomy :
Study of gross internal details of plant organs like root, stem, leaf, flower etc.

Long Answer Type Question

Question 1.
Give a comprehensive account on the scope of Botany in different fields giving an example for each.
Answer:
I) Agriculture :

1. Enhancement of crop yield through Green Revolution solves the problems like decreasing resources and increasing population.
2. New plant breeding techniques are useful to develop hybrid varieties in crop plants like Rice, Wheat, Maize, Sugarcane etc.
3. Phytopathology is helpful in prevention and eradication of several plant diseases.

II) Medicine :

1. Studies in Medicinal plants like Arnica, Cinchona, Neem, Datura, Rauwolfia, Ocimum are important to explore them for human health care.
2. Production of antibiotics, bioinsecticides, single cell proteins is made possible by study of these plants.

III) Environmental Issues :

1. Control of Green house effect by tree plantation and soil pollution by bio-remediation, recycling of nutrients by saprophytic organisms, usage of biofertilizers to avoid soil and water pollution caused by chemical fertilizers and prevention of soil erosion by sand binding plants.
2. Usage of algae (Chlorella) as food for astronauts in space research programmes and extraction of Iodine, agar-agar etc. from several sea weeds also indicate the scope of Botany for the Contemporary World.

IV) Commercial Products :
Knowledge of plants which yield commercially important and useful products like timber fibres, beverages such as coffe and tea, condiments, rubber, gums, resins, dyes, essential and aromatic oils is of great importance for their exploitation.

Andhra Pradesh BIEAP AP Inter 1st Year Botany Study Material 2nd Lesson Biological Classification Textbook Questions and Answers.

AP Inter 1st Year Botany Study Material 2nd Lesson Biological Classification

Very Short Answer Questions

Question 1.
What is the nature of cell-walls in diatoms?
Answer:
In Diatoms, the cell wall is made up of silica and thus the walls are Indestructible.

Question 2.
How are Viroids different from viruses? [Mar. 14]
Answer:

Question 3.
What do the terms phycobiont and mycobiont signify? [A.P. Mar, 17, Mar. 13]
Answer:
The Algal component in a lichen is called phycobiont. The fungal component in a lichen is called Mycobiont.

Question 4.
What do the terms ‘algal bloom’ and ‘Red Tides’ signify?
Answer:
In cyanobacteria :
The colonies and trichomes or filaments are surrounded by gelatinous sheath which often forms blooms in polluted water bodies called algal blooms.
Ex : Nostoc, Anabaena.

Red Dinoflagellates like “Gonyaulax” undergo rapid multiplication and make the sea “Red” so called Red Tides.

Question 5.
State two economically important uses of heterotrophic bacteria.
Answer:
Heterotrophic Bacteria help in making curd from milk, production of Antibiotics and Nitrogen fixation in legume roots.

Question 6.
What is the principle underlying the use of cyanobacteria in agricultural fields for crop improvement? [A.P. Mar. 15]
Answer:
Cyanobacteria are used in Agricultural fields for crop improvement because they help in Nitrogen fixation and make the soil fertile and also they show oxygenic photosynthesis.

Question 7.
Plants are autotrophic. Name some plants which are partially heterotrophic.
Answer:
Partial heterotrophic plants are viscum, loranthus, striga.

Question 8.
Who proposed five Kingdom classification? How many Kingdoms of this classification contain eukaryotes?
Answer:
R.H.Whittaker proposed five kingdom classification. In this classification, four kingdoms [Protista, Fungi, Plantae, Animalia are Eukaryotes.

Question 9.
Give the main criteria used for classification by Whittaker. [T.S. May. 18, Mar, 15]
Answer:
The main cricteria for five kingdom classification include cell structure, thallus organization. Mode of Nutrition, reproduction and phylogenetic relationships.

Question 10.
Name two diseases caused by Mycoplasmas. [A.P. May. 18]
Answer:
Mycoplasmas cause witches broom disease in plants, pleuropneumonia in cattle and v mycoplasmal urethritis in Humans.

Question 11.
What are slime moulds? Explain what is meant by plasmodium with reference to slime moulds.
Answer:
Slime moulds are saprophytic protists. The multinucleated mass of protoplasm is surrounded by a plasamamembrane under favourable conditions, they form an aggregation called plasmodium.

Short Answer Type Questions

Question 1.
What are the characteristic features of Euglenoids?
Answer:

1. Most of the euglenoids are Fresh Water organisms found in stagnant water.
2. They have a protein rich layer called pellicle which makes body flexible.
3. They have Two flagella, a short and a long one.
4. The anterior part of the cell bears an invagination consisting of cytostome, cytopharynx and reservoir.
5. Eye spot or photosensitive stigma is present in the reservoir.
6. They behave as heterotrophs when deprived of sunlight.
7. The reproduction is by lohgitudinal binary fission.

Question 2.
What are the advantages and disadvantages of Two kingdom classification?
Answer:
Advantages :

1. The two kingdom classification received considerable recognition from biologists and was in use for quite a long period of time.
2. Classification of organisms into plants, animals was easily done and was easy to understand.
3. The character that unified this whole kingdom was that all organisms included had a cell wall in their cells.

Disavantages :
1. There is no clear Cut distinction in the lower forms of life into plants and animals. Euglena for example is a unicellular organism having certain features of criminals and certain features of plants. If has a flagellum which is used for locomotion and food capturing. However it has chloroplasts like plant cells.

2. Chlomyclomonas is a unicellular algue. It is purely antotrophic but has 4 locomotor structures called flagella like protozoans.

3. The classification did not differentiate between the heterotrophic group, fungi and the autotrophic green plants through they also showed a characteristic difference in their wall composition. Hence two kingdom classification used for a lone time was found inadequate.

Question 3.
Give the salient features and importance of chrysophytes. [A.P. Mar, 15, 13]
Answer:
Chrysophytes includes diatoms and golden algae (desmids). They are found in freshwater as well as in marine water.’Most of them are photosynthetic. In diatoms the cell wall form two thin overlapping shells, epitheca over hypotheca which fit together as soap box. The walls are embedded with silica and thus the walls are indestructible. Diatoms leave larger amount of cell wall deposits in their habitat, this accumulation is referred as diatomaceous earth or kieselghur. They reproduce a sexually by Binary fission and sexually by gametes.

Importance :

1. The diatomaceous soil is used in polishing, filtration of oils 8 syrups.
2. Diatoms are the chief “producers” in the oceans.

Question 4.
Give a brief account of Dinoflagellates. [A.P. May, 18, Mar, 18] [T.S. Mar, 15]
Answer:

1. Dinoflagellates are mostly marine and photosynthetic.
2. The cell wall has stiff cellulose plates on the outer surface.
3. They have two flagella and produce spinning movements. So these protists are called “whirling whips”.
4. The nucleus has condensed chromosomes, which are without histones.
5. Some Dinoflagellates like Noctiluca show bioluminescence.
6. Red dinoflagellates like Gonyaulax undergo rapid multiplication and make the sea appear red
   (Redtides in Medeterranelian sea)
7. Toxins produced by them may kill fishes.

Question 5.
Write the role of Fungi in our daily life. [T.S. May, 18. Mar, 14]
Answer:
The role of Fungi in our dialy life show some uses and disuses. They are :
Uses :

1. Yeast are used to make bread and beer.
2. Some Fungi like penicillium are the source of antibiotics. (Penicilin)
3. Some Fungi like Agaricus are edible mushrooms.

Disuses :

1. Some Fungi cause rot of orange fruits
2. Spoilage of bread
3. White spots are seen in musterd leaves by Albugo.
4. Some Fungi (Puccinia) cause rust in wheat.

Long Answer Type Questions

Question 1.
Give the salient features and comparative account of different classes of fungi studied by you.
Answer:
A) Phycomycetes :

1. They are found in Aquatic habitats and on decaying wood or as obligate parasites on plants. They arealso called algal fungi.
2. The mycelium is aseptate and coenocytic.
3. A sexual reproduction takes place by zoospores or by aplanospores.
4. Zygospores are formed by the fusion of two gametes which may similar (Isogamous) or dissimilar (Anisogamous) or oogamous.
   Ex : Mucor, Rhizopus, Albugo.

B) Ascomycetes :

1. They are commonly called “sac fungi”
2. They are unicelluar (yeast) or multicellular (Penicillium).
3. They are saprophytic, decomposers, parasitic or coprophilous (growing on dung).
4. The mycelium is Branched and septate.
5. The reproduce asexually by conidia, produced on conidiophores.
6. Sexual spores are called ascospores Ex : Aspergillus, pencillium, ckiviceps.

C) Basidiomycetes :

1. They are commonly known as Mushrooms, bracket fungi or puffballs or club fungi.
2. They grow in soil, on logs and tree stumps and in living plant bodies as parasites.
   Ex : Rusts.
3. The mycelium is branched and septate.
4. The asexual spores are not found but common method is fragmentation.
5. Sex organs are absent.
6. Plasmogamy takes place by the fusion of two vegetative cells of different strains or genotypes.
7. Karyogamy and Meiosis take place in the basidium producing basidiospores.
   Ex : Agaricus, ustilago, polyporus Lycoperdon.

D) Deuteromycetes :

1. They are commonly known as imperfect fungi.
2. Some members are saprophytes or parasites, while a large members are decomposers.
3. The mycelium is branched and septate.
4. They reproduce asexually and vegetatively.
5. When the sexual stages were discovered, they were moved into another classes, asco or basidiomycetes.
   Ex : Alternaria, Colletotrichum, Trichoderma.

Question 3.
Describe briefly different groups of Monerans you have studied.
Answer:
They indued Alio prokaryotes like Archaebacteria, Eubacteria, Mycoplasma and Actinomycetes.

I. Archaebacteria :

1. They live in salty areas, hot springs or in Marshy places.
2. The cell wall contains pseudomurein.
3. The cell membrane contains branched chain lipids.
4. Methanogens are present in the gut of ruminant animals, and are responsible for the production of methane gas from the dung.

II. Eubacteria :

1. They occur almost everywhere, such as hotsprings, deserts, snow and deep oceans as parasites and as symbionts.
2. They are classified-into spherical coccus, rod shaped bacillus, the comma shaped vibrio and the spiral shaped spirillum, based on their shape.
3. The cell wall is made up of peptidoglycan.
4. The cell membrane shows infoldings called mesosomes.
5. They contain 70s type of ribosomes along with naked genetic material (nucleoid).
6. Some of eubacteria are autotrophic and the vast majority are heterotrophs.
7. Cyanobacteria like Nostoc and Anabaena are Unicellular, colonial or filamentous, aquatic or terrestrial algae.
8. They often forms blooms in polluted water bodies. Some of them can fix Atmospheric Nitrogen in specialised cells called Heterocysts.

III. Mycoplasma :

1. They completely lack a cell wall and are pleomorphic.
2. They are smallest living cells and can survive without oxygen.
3. They cause diseases in plants [witches broom]; in cattle (pleuropneumonia) and in humans (Mycoplasmal urethritis).

IV. Actinomycetes :

1. They are branched, filamentous bacteria.
2. The cell wall contains mycolic acid.
3. Most of them are saprophytic and decomposers.
4. Some are (Mycobacterium and corynebacterium) parasites.
5. A number of antibiotics are produced from the genus streptomyces.

Question 3.
Enumerate the salient features of different groups in protista.
Answer:
I. Chrysophytes :

1. Chrysophytes includes diatoms and golden algae (desmids).
2. They are found in freshwater as well as in marine water.
3. Most of them are photosynthetic.
4. In diatoms the cell walls form two thin overlapping shells, epitheca over hypotheca which fit together as soap box.
5. The walls are embedded with silica and thus the walls are indestructible.
6. Diatoms leave larger amount of cell wall deposits in their habitat, this accumulation is referred as diatomaceous earth or kieselghur.
7. They reproduce asexually by Binary fission and sexually by gametes. ‘

II. Dinoflagellates :

1. Dinoflagellates are mostly marine and photosynthetic.
2. The cell was has stiff cellulose plates on the outer surface.
3. They have two flagella and produce spinning movements. So these protists are called “whirling whips”.
4. The nucleus has condensed chromosomes, which are without histones.
5. Some Dinoflagellates like Noctiluca show bioluminescence.
6. Red dinoflagellates like Gonyaulax undergo rapid multiplication and make the sea appear red (Redtides in Medterranian sea)
7. Toxins produced by them may kill fishes.

III. Euglenoids :

1. Most of the euglenoids are Fresh Water organisms found in stagment water.
2. They have a protein rich layer called pellicle which makes body flexible.
3. They have Two flagella, a short and a long one.
4. The anterior part of the cell bears an invagination, consisting of cytostome, cytopharynx and reservoir.
5. Eye spot or photosensitive stigma is present in the reservoir.
6. They behave as heterotrophs when deprived of sunlight.
7. The reproduction is by longitudinal binary fission.

IV. Slime moulds :

1. They are saprophytic protists. The multinucleated mass of protoplasm is surrounded by a plasamamembrane.
2. Under suitable conditions, they form an aggregation called plasmodium.
3. During unfavourable conditions, the plasmodium differentiates and forms fruiting bodies bearing spores at their tips.
4. The spores are extremely resistant and are dispersed by air.

V. Protozoans :

1. They live as predators or parasites.
2. They do not contain cell wall.
3. The protoplason is surrounded by plasma membrane.
4. Among them. Amoeboid protozoans live in fersh water, sea water or moist soil. They move and capture their prey by pseudopodia.
   Ex : Entamoeba.
5. Flagellated protozoans are either free living or parasitic.
6. They have flagella.
7. The parasitic forms cause diaseases such as sleeping sickness.
   Ex : Trypanosoma.
8. Ciliated Protozoans : They are aquatic and actively moving organisms by having cilia.
9. They have a cavity that opens to outside of the cell surface.
   Ex: Paramoecium.

IV. Sporozoans :
They have an Infectious spore like stage in their life cycle.
Ex : Plasmodium (Malarial parasite) causes Malaria in humans.

Intext Questions

Question 1.
State two economically important uses of :
a) Heterotrophic bacteria b) Archaebacteria
Answer:
a) Heterotrophic bacteria :
They help in making curd from milk, production of Antibiotics and \ Nitrogen fixation in legume roots.

b) Archaebacteria :
1) Produce methane 2) Used by humans in biotechnoogy.

Question 2.
Give a comparative account of the classes of Kingdom Fungi on the basis of the following :
i) mode of nutrition
ii) mode of reproduction.
Answer:
i) mode of nutrition :
a) Phycomycetes : Obligate parasites.
b) Ascomycetes : Saprophytic, decomposers.
c) Basidiomycetes : Parasites.

d) Deuteromycetes :
Saprophytes, decomposers, ii) mode of reproduction :
a) Phycomycetes : Asexually by zoospores or aplanospores, sexually by gametes.
b) Ascomycetes : Asexually by conidia, sexually by ascospores.
c) Basidiomycetes : Asexually by fragmentation, sexually by fusion of two somatic cells.
d) Deuteromycetes : Asexually by conidia.

Question 3.
Give a brief account of viruses with respect to their structure and nature of genetic material. Also name four common viral diseases.
Answer:
Viruses are made up of Nucleic acid and protein. The Nucleic acid could be either RNA or DNA. The protein part is called capsid which encloses the Nucleic acid. Tobacco Mosaic virus and Human Immuno Virus (HIV) contains RNA as genetic material. Bacteriophages, contain DNA as genetic material.

Common viral diseases are –

1. Tobacco Mosaic virus.
2. Potato spindle Tuber disease.
3. Human Immuno virus.
4. Scrapie disease of sheep.

Question 4.
Organise a discussion in your class on the topic – Are viruses living or non-living?
Answer:
Viruses are not truly ‘living’. They exist in crystal form outside the host. They are called obligate parasites.

Question 5.
Suppose you accidentally find an old preserved permanent slide without a label and in your effort to identify it, you place the slide under microscope and observe the following features :
a) unicellular body
b) well defined nucleus
c) biflagellate condition – one flagellum lying longitudinally and the other transversely.
What would you identify it as? Can you name the kingdom it belongs to?
Answer:
Protistian cell. They belongs to kingdom protista.

Question 6.
Polluted water bodies have usually high abundance of plants like Nostoc and Oscillatoria. Give reasons.
Answer:
Abundence of reserved food materials.
– Increase the level of dissolved O₂ in their environment.
– N₂ fixing capacity.

Question 7.
Cyanobacteria and heterotrophic bacteria have been clubbed together in Eubacteria of Kingdom Monera as per the five kingdom classification, even though the two are vastly different from each other. Is this grouping of the two types of taxa in the same kingdom justified? If so why?
Answer:
Grouping of the two types of tax a in the same kingdom is justified because both organisms contain ‘nif’ genes and are involved in Nitrogen fixation.

Question 8.
What observable features in Trypanosoma would make you classify it under kingdom protista?
Answer:

1. They are free living or parasitic.
2. They have flagella.

Question 9.
At a stage of their life cycle, ascomycetous fungi produce the fruiting bodies like cleistothecium perithecium or apothecium. How are these three types of fruiting bodies differ from each ohter?
Answer:
The globose ascocarp without opening is called cleistothecium.
The flask shaped ascocarp with an apical opening is called perithecium.
The cup or saucer shaped ascocarp is called apothecium.

Andhra Pradesh BIEAP AP Inter 1st Year Botany Study Material 1st Lesson The Living World Textbook Questions and Answers.

AP Inter 1st Year Botany Study Material 1st Lesson The Living World

Very Short Answer Questions

Question 1.
What does ICBN Stand for? [T.S. Mar, 18]
Answer:
ICBN stand for “International Code for Botanical Nomenclature”.

Question 2.
What is Flora? [T.S. Mar, 15]
Answer:
Actual account of habitat, distribution and systematic listing of plants of a given area is called Flora.

Question 3.
Define metabolism. What is the difference between anabolism and catabolism?
Answer:
Sum total of all the chemical reactions occuring in the body of an organism is called Metabolism.

Question 4.
Which is the largest botanical garden in the world? Name a few well known botanical gardens in India.
Answer:
Royal Botanical Garden (RBG) at kew (England) is the largest Botanical Garden in the world. Well Known Botanical gardens in India are

1. Indian Botanical gardens, Howrah.
2. National Botanical Research Institute, Lucknow.

Question 5.
Define the terms couplet and lead in taxonomic key. [A.P. Mar, 15]
Answer:
The contrasting characters generally in a pair is called “couplet”. Each statement in the key is called “Lead”.

Question 6.
What is meant by manuals and monographs?
Answer:
Manual is a small book specially designed for ready reference. Monographs contain Information on any one taxon.

Question 7.
What is systematics? [T.S. Mar, 18]
Answer:
“The study of different kinds of organisms, their diversities and also the relationship among them”.

Question 8.
Why are living organisms classified?
Answer:
Living organisms are classified to know their growth, reproduction, ability to sense environment and mount a suitable response, metabolism, ability to self replicate, interaction and emergence.

Question 9.
What is the basic unit of classification? Define it. [A.P. Mar, 17, 14, 13]
Answer:
“Species”.

“Species is defined as a group of Individual organisms with fundamental similarities”.

Question 10.
Give the scientific name of Mango. Identify the generic name and specific epithet. [T.S. Mar, 17]  [A.P. May, 18]
Answer:
Mangifera indica. Its Generic name is “Mangifera” and specific epithet is “indica”.

Question 11.
What is growth? What is the difference between the growth in living organisms and growth in non-living objects?
Answer:
Growth is a permanent and irreversible increase in the size of a living organism.

In Living organisms, growth is from Inside. Where as in Non-living objects like Mountains and sand mounds, growth occurs by accumulation on of material on the outer surface.

Short Answer Type Questions

Question 1.
What is meant by Identification and nomenclature? How is a key helpful in the identification & classification of an organism?
Answer:
Identification is defined as, “Whether a collected organism is entirely new or already known”. Nomenclature is defined as “providing a scientific name to an Identified organism”.

Key is a taxonomical aid used for Identification of plants and animals based on the similarities and dissimilarities. The keys are based on the contrasting characters generally in a pair called couplet. It represents the choice made between two opposite options. Each statement in the key is called lead, separate taxonomic keys are required for each taxonomic category such as family, genus and species for Identification purposes. Keys are generally analytical in nature.

Flora, Manuals, Monographs, and catelogues are also help in correct Identification of plants of a given area.

Question 2.
What are taxonomical aids? Give the importance of herbaria and museums.
Answer:
Taxonomical aids are the collection of actual specimens of plant and animal species which are useful in agriculture, forestry. Industry and in knowing bio-resources and their diversity.

Herbarium is a store house of collected plant specimens that are dried, pressed, and preserved on sheets. These sheets are used for future use and also carry a label providing information about data and place of collection, English, local and botanical names, family, collector’s name. Herbaria also serve as quick referal systems in taxonomical studies. Museums are generally set up in Educational Institutes. Museums have collections of preserved plant and animals specimens for study and reference.

Question 3.
Define a taxon. Give some examples of taxa at different hierarchial levels.
Answer:
Taxon is defined as, Any unit of category in a Taxonomic system. There are different taxonomic levels such as
a) Species – It is the lowest category in which a group of Individual organisms w|th fundamental similarities are placed.
Example : Mangifera indica (Mango), indica is the specific epithet.

b) Genus – A group of related species which has more characters in common in comparison to species of other genera.
Example : Potato and brinjal are two different species but belong to the genus solanum.

c) Family – It has a group of related genera with still less number of similarities as compared to genus and species.
Example : Solanum, Nicotiana and Datura are three different genera but placed in the family solanaceae.

d) Order – It is the assemblage of families which exhibit a few similar characters.
Example : Based on the floral characters.Solanaceae and Convolvulaceae are included in the order polemoniales.

Question 4.
How are botanical gardens useful in conserving biodiversity? Define the terms Flora, manuals, monographs and catalogues?
Answer:
Botanical gardens have collections of living plants for reference. Plant species in these gardens are grown for identification purposes and each plant is labelled indicating its botanical name and its family.

Flora :
It contains the actual account of habitat, distribution and systematic listing of plants of a given area.

Manual :
It is a small book containing the information for identification of names of species found in an area.

Monograph :
They contain information on any one taxon.

Catelogues :
Books which help in correct identification of plants.

Question 5.
Explain binomial nomenclature.
Answer:
Naming the plants with two words is called Binomial nomenclature. This system was given by Carolus Linnaeus. Naming is done by following some rules. They are

1. Biological names are generally in Latin and written in Italics.
2. The first word represents the Genus while the second word represents the species.
3. Both the words, when handwritten, are separately underlined.
4. The first word should starts with a capital letter while second word should starts with a small letter.
5. The name of the auther should be at the end of scientific name in abbreviated form.

Long Answer Type Questions

Question 1.
What is meant by living? Give a detailed account of any four defining features of life forms.
Answer:
The state of Material complex or individual characterized by the capacity to perform certain functional activities including metabolism, growth, and Reproduction.

1) Growth :
All living organisms increase in mass and increase in number. In plants, growth occurs by cell division, continuously throughout their life span. Unicellular organisms also grow in size until they divide by cell division.

2) Reproduction :
“Reproduction means progeny possessing feautures more or less similar to those of parents organisms, reproduce asexually and also by sexual methods. Fungi reproduce asexually by spores. Filamentous algae and Protonema of mosses reproduce by Fragmentation. In unicellular oganisms like Bacteria, unicellular algae or Amoeba reproduction is synonymous with growth. There are many organisms which do not reproduce. Hence reproduction also cannot be an all-inclusive defining characterestic of living organisms.

3) Metabolism :
The sum total of all the chemical reaction occuring in the body of a living organisms is called metabolism. All plants, Animals, Fungi and Microbes exhibit metabolism. No nonliving obejct exhibit metabolism.

4) Ability to sense their surroundings :
All living organisms, have the ability to sense their surroundings or environment and respond to Physical, Chemical or Biological stimuli. This response to environmental stimuli is called Irritability. Plants respond to external factors like light, water, temperature other organisms, pollutants etc. All organismsare aware of their surroundings and is called consciousness. Human beings has self consciousness except patients.

Question 2.
Define the following terms with examples.
i) Class ii) Family iii) Order iv) Genus v) Division
Answer:
i) Class :
A group of related orders constitutes class.
Ex : In plant kingdom, orders like Malvales, Rosales, Polemoniales are included in the class
Dicotyledonae.

ii) Family :
A group of related Genera’ is called family. They are characterised on the basis of both vegetative and reproductive features of plant species.
Ex : Solanum, Nicotiana and Datura are three different Genera but are placed in the family Solanaceae.

iii) Order :
Assemblage of families which exhibit a few similar characters is called order.
Ex : Families like convolvualeceae, Solanaceae are included in the order polemoniales based on the floral characters.

iv) Genus :
A groupo of related species which has more characters in common in comparison to species of other Genera is called Genus.
Ex : Potato (tuberosum) and Brinjal (melongena) are two different species but are placed in the same Genus, ‘Solanum’.

v) Divsion :
‘A group of related .classes’ is called Division.
Ex : Dicotyledonae and Monocotyl’edonae are two classes with a few similar characters are placed in Division spermatophyta.

Intext Questions

Question 1.
Some of the properties of tissues are not constituents of their cells. Give two examples to support the statement.
Answer:

1. Properties of tissues arise as a result of Interactions among the constituent cells.
2. Properties of cellular organelles arise as a result of Interactions among the molecular components comprising the organelle.

Question 2.
What do we learn from identification of individuals and populations?
Answer:
It is the prime source of taxonomic studies and also knows about or bioresources and their diversity.

Question 3.
Given below is the scientific name of Mango. Identify the correctly written name.
Mangifera Indica
Mangifera indica
Answer:
Mangifera indica.

Question 4.
Can you identify the correct sequence of taxonomical categories?
a) Species, Order, Division, Kingdom
b) Genus, Species, Order, Kingdom
c) Species, Genus, Order, Phylum
Answer:
C is correct.

Question 5.
Define the following terms :
i) Species ii) Class iii) Family iv) order v) Genus.
Answer:
i) Species :
A group of Individual organisms with fundamental similarities.

ii) Class :
An assemblage of related orders is called class.

iii) Family :
A group of related genera with less number of similarities as compared to genus and species.

iv) order :
An assemblage of families.

v) Genus :
A group of related species which has more characters in comparison to species of other Genera.

Question 6.
Illustrate the taxonomical hierarchy with suitable example of a plant.
Answer:
Kingdom = Plant kingdom
Division = Spermatophyta
Class = Dicotyledonae
Order = Sapindales
Family = Anacardiaceae
Genus = Mangifera
Species = Indica

Question 7.
What are the distinctive characteristics exhibited by living organisms? Describe them in brief.
Answer:
Growth, reproduction, ability to sense environment, Metabolism, ability to self duplicate.

Growth :
Increase in mass and Increase in number of Individuals.

Reproduction :
It is the production of progeny possessing features more or less similar to those of parents.

Metabolism :
It is the sum total of all the chemical reactions occurring in the body of an organism.

Question 8.
Life forms exhibit ‘unity in diversity’ – Discuss with your teacher.
Answer:
An important aspect of life is its vast diversity built on a base of underlying unity. For example, organisms as outwardly dissimilar as a bacterium, a human and an Oak tree are all composed of the same basic structural element, the cell, which in turn have many similar subcellular and molecular components.

Question 9.
List out the principles followed to provide scientific names for newly found organism?
Answer:

1. Identification of organisms whether it is entirely new or already known.
2. Particular organism should be named by same name all over the world. Thus nomenclature is providing a scientific name to an identified organism.

Telangana & Andhra Pradesh BIEAP TS AP Intermediate Inter 1st Year Economics Study Material Textbook Solutions Guide PDF Free Download, TS AP Inter 1st Year Economics Blue Print Weightage 2022-2023, Telugu Academy Intermediate 1st Year Economics Textbook Pdf Download, Questions and Answers Solutions in English Medium and Telugu Medium are part of AP Inter 1st Year Study Material Pdf.

Students can also read AP Inter 1st Year Economics Syllabus & AP Inter 1st Year Economics Important Questions for exam preparation. Students can also go through AP Inter 1st Year Economics Notes to understand and remember the concepts easily.

AP Intermediate 1st Year Economics Study Material Pdf Download | Jr Inter 1st Year Economics Textbook Solutions

• Chapter 1 Introduction
• Chapter 2 Theory of Consumers Behaviour
• Chapter 3 Theory of Demand
• Chapter 4 Theory of Production
• Chapter 5 Theory of Value
• Chapter 6 Theory of Distribution
• Chapter 7 National Income
• Chapter 8 Macro Economic Aspects
• Chapter 9 Money, Banking and Inflation
• Chapter 10 Economic Statistics

TS AP Inter 1st Year Economics Weightage Blue Print 2022-2023

TS AP Inter 1st Year Economics Weightage 2022-2023 | TS AP Inter 1st Year Economics Blue Print 2022

Intermediate 1st Year Economics Syllabus

TS AP Inter 1st Year Economics Syllabus

Paper – I Introductory Economic Theory

Unit – I Introduction
a) Origin and meaning of Economics –
b) Definitions of Economics; Adam Smith, Alfred Marshall, Lionel Robbins, Paul Samuelson, & Jocob Viner. Concept of Economics – Micro & Macro Economics Deductive and Inductive Method, Static and Dynamic Analysis, Positive and Normative Economics. Goods: (Free, Economic, Consumer, Producer, and Intermediary), Wealth, Income, Utility, Value, Price, wants and welfare.

Unit – II Theory of Consumers Behaviour
a) Cardinal and Ordinal Utility, the law of Diminishing Marginal Utility – Limitations – Importance; law of Equi-Marginal Utility Limitations and –Importance of the Law, Indifference Curve Analysis – Properties and Consumer’s Equilibrium.

Unit – III Theory of Demand
a) Meaning – Demand Function – Determinants of Demand, Demand Schedule – Demand Curve, Law of Demand, Exceptions to Law of Demand – Causes for the downward slope of the demand curve, Types of Demand – Price Demand, Income Demand, and Cross Demand,
b) Elasticity of Demand – Meaning and Types – Price Elasticity, and Income Elasticity and Cross Elasticity – Price Elasticity-Types; Measurement of Price Elasticity of Demand- Point Method. Arc Method, Total Outlay Method. Determinants of Elasticity of Demand; Importance of Elasticity of Demand

Unit – IV Theory of Production
a) Meaning – Production Function – Factors of Production; Short-run and Long-run Production Function; Law of variable proportions
b) Law of returns to scale; Economies of Scale – Internal and External
c) Supply – Supply Function – Determinants of Supply –– Law of Supply
d) Cost Analysis – Basic Concepts of Costs- (Money, Real, Opportunity, Fixed and Variable, Total, Average and Marginal costs)
e) Revenue Analysis – Revenue under perfect and imperfect competition

Unit – V Theory of Value
a) Meaning and Classification of Markets – Perfect competition – features – price determination- Short-run and Long-run equilibrium of a firm and Industry b) Imperfect Competition – Monopoly – Price Determination – Price-Discrimination-Monopolistic Competition- Features- Meaning of Oligopoly – Duopoly

Unit – VI Theory of Distribution
a) Determination of Factor Prices – Marginal Productivity Theory
b) Rent – Ricardian theory of Rent – Modern theory – Quasi Rent – Transfer earnings.
c) Wages – Meaning and types of wages – Money and Real wages
d) Interest- Meaning – Gross and Net interests
e) Profits – Meaning – Gross and Net profits

Unit – VII National Income
a) Definitions of National Income and Concepts
b) Measurement of National Income – Census of Product Method – Census of Income Method – Census of Expenditure Method
c) Methods of Measuring National Income in India; Problems and importance

Unit – VIII Macro Economics Aspects
a) Classical theory of Employment –J.B. Say Law of Markets- Limitations – J.M. Keynes Effective Demand.
b) Public Economics – Public Revenue – Public Expenditure – Public debt – Components of Budget.

Unit – IX Money, Banking and Inflation
a) Money – Definitions and Functions of money – Types of Money
b) Banking – Commercial Banks – Functions; Central Bank – Functions – Reserve Bank of India – Net Banking.
c) Inflation – Definitions – Types – Causes and Effects of inflation – Remedial Measures

Unit – X Statistics for Economics
a) Meaning, Scope and Importance of Statistics in Economics with Diagrams (Bar diagrams and Pie diagrams) Measures of central tendency – Mean, Median, Mode.

We hope that this Telangana & Andhra Pradesh BIEAP TS AP Intermediate Inter 1st Year Economics Study Material Textbook Solutions Guide PDF Free Download 2022-2023 in English Medium and Telugu Medium helps the student to come out successful with flying colors in this examination. This Jr Inter 1st Year Economics Study Material will help students to gain the right knowledge to tackle any type of questions that can be asked during the exams.

Telangana & Andhra Pradesh BIEAP TS AP Intermediate Inter 1st Year Accountancy Study Material Textbook Solutions Guide PDF Free Download, TS AP Inter 1st Year Accountancy Blue Print Weightage 2022-2023, Telugu Academy Intermediate 1st Year Accountancy Textbook Pdf Download, Questions and Answers Solutions in English Medium and Telugu Medium are part of AP Inter 1st Year Study Material Pdf.

Students can also read AP Inter 1st Year Accountancy Syllabus & AP Inter 1st Year Accountancy Important Questions for exam preparation. Students can also go through AP Inter 1st Year Accountancy Notes to understand and remember the concepts easily.

AP Intermediate 1st Year Accountancy Study Material Pdf Download | Jr Inter 1st Year Accountancy Textbook Solutions

• Chapter 1 Book Keeping and Accounting
• Chapter 2 Accounting Principles
• Chapter 3 Double Entry Book Keeping System
• Chapter 4 Journal
• Chapter 5 Ledger
• Chapter 6 Subsidiary Books
• Chapter 7 Journal Proper
• Chapter 8 Cash Book
• Chapter 9 Bank Reconciliation Statement
• Chapter 10 Trail Balance
• Chapter 11 Rectification of Errors
• Chapter 12 Final Accounts
• Chapter 13 Final Accounts with Adjustments

TS AP Inter 1st Year Accountancy Weightage Blue Print 2022-2023

TS AP Inter 1st Year Accountancy Weightage 2022-2023 | TS AP Inter 1st Year Accountancy Blue Print 2022

Intermediate 1st Year Accountancy Syllabus

TS AP Inter 1st Year Accountancy Syllabus

Chapter 1 Book Keeping and Accounting

• 1.1 Introduction
• 1.2 Book Keeping
• 1.3 Accounting
• 1.4 Basic Accounting Terms

Chapter 2 Accounting Principles

• 2.1 Accounting Principles
• 2.2 Accounting Concepts
• 2.3 Accounting Conventions
• 2.4 Accounting Standards

Chapter 3 Double Entry Book Keeping System

• 3.1 Introduction
• 3.2 Meaning
• 3.3 Advantages
• 3.4 Account
• 3.5 Classification of Accounts

Chapter 4 Journal

• 4.1 Meaning
• 4.2 Proforma
• 4.3 Illustrations

Chapter 5 Ledger

• 5.1 Meaning
• 5.2 Advantages of Ledger
• 5.3 Posting

Chapter 6 Subsidiary Books

• 6.1 Meaning of the Subsidiary Books
• 6.2 The Need / Advantages of Subsidiary Books
• 6.3 Types of Subsidiary Books
• 6.4 Preparation of Subsidiary Books
  • 6.4.1 Purchase Book
  • 6.4.2 Purchase Returns Book
  • 6.4.3 Sales Book
  • 6.4.4 Sales Return Book
  • 6.4.5 Cash Book
  • 6.4.6 Bills Receivable Book
  • 6.4.7 Bills Payable Book
  • 6.4.8 Journal Proper

Chapter 7 Journal Proper

• 7.1 Meaning
• 7.2 Advantages
  • 7.2.1 Opening Entries
  • 7.2.2 Purchases of Assets on Credit
  • 7.2.3 Sale of Asset on Credit
  • 7.2.4 Rectification entries
  • 7.2.5 Adjustment entries
  • 7.2.6 Closing journal entries
  • 7.2.7 Transfer entries
  • 7.2.8 Other entries

Chapter 8 Cash Book

• 8.1 Meaning of Cash Book
• 8.2 Characteristics and Advantages
  • 8.2.1 Characteristics
  • 8.2.2 Advantages
• 8.3 Importance
• 8.4 Various kinds of Cash Book and their Preparation
  • 8.4.1 Simple Cash Book
  • 8.4.2 Double column Cash Book
  • 8.4.3 Triple column Cash Book
  • 8.4.4 Petty Cash Book

Chapter 9 Bank Reconciliation Statement

• 9.1 Introduction
• 9.2 Nature Of The Cash Book And Bank Pass Book (Bank Statement)
• 9.3 Meaning and Advantages of Bank Reconciliation Statement
• 9.4 Procedure for Preparation of Bank Reconciliation Statement
• 9.5 Reasons for Difference
• 9.6 Preparation of Bank Reconciliation Statement
  • 9.6.1 Favourable Balances
  • 9.6.2 Unfavourable Balance or Overdraft Balance
  • 9.6.3 When extracts from Cash Book and Pass Book are given

Chapter 10 Trail Balance

• 10.1 Meaning
• 10.2 Features or Characteristics
• 10.3 Merits
• 10.4 Limitations
• 10.5 Types of Preparation
• 10.6 Proforma
• 10.7 Key Points

Chapter 11 Errors and their Rectifications

• 11.1 Errors
• 11.2 Types of Errors
• 11.3 Rectification of Errors
• 11.4 Suspense Account

Chapter 12 Final Accounts

• 12.1 Meaning
• 12.2 Objectives
• 12.3 Advantages and Limitations
• 12.4 Capital and Revenue Items
• 12.5 Preparation of Trading Account
• 12.6 Preparation of Profit & Loss Account
• 12.7 Balance Sheet

Chapter 13 Final Accounts with Adjustments

• 13.1 Meaning
• 13.2 Types of Adjustments
• 13.3 Summary of Adjustments
• 13.4 Accounting Treatment to the Adjustments given in Trial Balance

We hope that this Telangana & Andhra Pradesh BIEAP TS AP Intermediate Inter 1st Year Accountancy Study Material Textbook Solutions Guide PDF Free Download 2022-2023 in English Medium and Telugu Medium helps the student to come out successful with flying colors in this examination. This Jr Inter 1st Year Accountancy Study Material will help students to gain the right knowledge to tackle any type of questions that can be asked during the exams.

Telangana & Andhra Pradesh BIEAP TS AP Intermediate Inter 1st Year Commerce Study Material Textbook Solutions Guide PDF Free Download, TS AP Inter 1st Year Commerce Blue Print Weightage 2022-2023, Telugu Academy Intermediate 1st Year Commerce Textbook Pdf Download, Questions and Answers Solutions in English Medium and Telugu Medium are part of AP Inter 1st Year Study Material Pdf.

Students can also read AP Inter 1st Year Commerce Syllabus & AP Inter 1st Year Commerce Important Questions for exam preparation. Students can also go through AP Inter 1st Year Commerce Notes to understand and remember the concepts easily.

AP Intermediate 1st Year Commerce Study Material Pdf Download | Jr Inter 1st Year Commerce Textbook Solutions

• Chapter 1 Concept of Business
• Chapter 2 Business Activities
• Chapter 3 Forms of Business Organization
• Chapter 4 Joint Hindu Family Business & Co-op Society
• Chapter 5 Partnership
• Chapter 6 Joint Stock Company – Formation
• Chapter 7 Formation of a Company
• Chapter 8 Sources of Business Finance-I
• Chapter 9 Sources of Business Finance-II
• Chapter 10 Micro, Small and Medium Enterprises (MSMEs)
• Chapter 11 Multi National Corporations (MNCs)
• Chapter 12 Emerging Trends in Business

TS AP Inter 1st Year Commerce Weightage Blue Print 2022-2023

TS AP Inter 1st Year Commerce Weightage 2022-2023 | TS AP Inter 1st Year Commerce Blue Print 2022

Intermediate 1st Year Commerce Syllabus

TS AP Inter 1st Year Commerce Syllabus

Chapter 1 Concept of Business

• 1.1 Introduction to Business
• 1.2 Classification of Economic Activities
• 1.3 Characteristic Features of Business
• 1.4 Objectives of Business
• 1.5 Social Responsibility of Business

Chapter 2 Business Activities

• 2.1 Industry
• 2.2 Commerce
• 2.3 Hindrances involved in Commerce
• 2.4 Branches of Commerce
• 2.5 Inter relationship between Industry, Trade and Commerce
• 2.6 Distinction between Industry, Commerce and Trade

Chapter 3 Forms of Business Organisation

• 3.1 Concept of Business organisation
• 3.2 Forms of Business organisation
• 3.3 Sole Proprietorship

Chapter 4 Joint Hindu Family Business and Cooperative Society

• 4.1 Joint Hindu Family form of Business Organisation
• 4.2 Cooperative Society

Chapter 5 Partnership

• 5.1 Meaning and Definition
• 5.2 Features
• 5.3 Types of Partners
• 5.4 Advantages and Limitations
• 5.5 Registration of Partnership
• 5.6 Partnership Deed
• 5.7 Rights and Duties of Partners
• 5.8 Dissolution of Partnership Firms

Chapter 6 Joint Stock Company – Formation

• 6.1 Joint Stock Company
• 6.2 Features
• 6.3 Classification of Companies
• 6.4 Distinction between Private Company and Public Company
• 6.5 Advantages and Disadvantages

Chapter 7 Formation of a Company

• 7.1 Steps In Formation of a Company
• 7.2 Promotion
• 7.3 Functions of Promoters
• 7.4 Types of Promoters
• 7.5 Incorporation of a Company or registration
• 7.6 Capital subscription
• 7.7 Commencement of Business
• 7.8 Memorandum of association
• 7.9 Articles of association
• 7.10 Prospectus
• 7.11 Minimum Subscription
• 7.12 Certificate of Commencement of Business

Chapter 8 Sources of Business Finance-I

• 8.1 Meaning of Business Finance
• 8.2 Nature of Business Finance
• 8.3 Need for and Significance of Business Finance
• 8.4 Classification of Sources of Funds
• 8.5 Factors Determining the choice of Sources of Finances

Chapter 9 Sources of Business Finance-II

• 9.1 Non-institutional Sources of Finance
• 9.2 Institutional sources of Finance
• 9.3 International sources of Finance

Chapter 10 Micro, Small and Medium Enterprises (MSMEs)

• 10.1 Meaning and definition of Enterprise and MSMEs
• 10.2 Registration requirements under the MSMED Act, 2006
• 10.3 Significance of MSMEs
• 10.4 Privileges offered To Micro, Small And Medium Enterprises
• 10.5 Other Promotional Measures For MSMEs

Chapter 11 Multi National Corporations (MNCs)

• 11.1 Meaning and definitions
• 11.2 Necessity of Globalization
• 11.3 Multi-national Corporations
• 11.4 Features of MNCs
• 11.5 Advantages and Disadvantages of MNCs

Chapter 12 Emerging Trends in Business

• 12.1 Meaning and Definition of E-Business
• 12.2 Scope of E-business
• 12.3 Benefits of E-business
• 12.4 Opportunities and challenges of business in 21st Century
• 12.5 Opportunities
• 12.6 Challenges

We hope that this Telangana & Andhra Pradesh BIEAP TS AP Intermediate Inter 1st Year Commerce Study Material Textbook Solutions Guide PDF Free Download 2022-2023 in English Medium and Telugu Medium helps the student to come out successful with flying colors in this examination. This Jr Inter 1st Year Commerce Study Material will help students to gain the right knowledge to tackle any type of questions that can be asked during the exams.

Telangana & Andhra Pradesh BIEAP TS AP Intermediate Inter 1st Year Civics Study Material Textbook Solutions Guide PDF Free Download, TS AP Inter 1st Year Civics Blue Print Weightage 2022-2023, Telugu Academy Intermediate 1st Year Civics Textbook Pdf Download, Questions and Answers Solutions in English Medium and Telugu Medium are part of AP Inter 1st Year Study Material Pdf.

Students can also read AP Inter 1st Year Civics Syllabus & AP Inter 1st Year Civics Important Questions for exam preparation. Students can also go through AP Inter 1st Year Civics Notes to understand and remember the concepts easily.

AP Intermediate 1st Year Civics Study Material Pdf Download | Jr Inter 1st Year Civics Textbook Solutions

• Chapter 1 Scope and Significance of Political Science
• Chapter 2 State
• Chapter 3 Nationalism
• Chapter 4 Law
• Chapter 5 Liberty and Equality
• Chapter 6 Rights and Responsibilities
• Chapter 7 Justice
• Chapter 8 Citizenship
• Chapter 9 Democracy
• Chapter 10 Secularism
• Chapter 11 Constitutions
• Chapter 12 Government

TS AP Inter 1st Year Civics Weightage Blue Print 2022-2023

TS AP Inter 1st Year Civics Weightage 2022-2023 | TS AP Inter 1st Year Civics Blue Print 2022

Intermediate 1st Year Civics Syllabus

TS AP Inter 1st Year Civics Syllabus

Chapter 1 Scope and Significance of Political Science
Meaning of Political Science, Origin of Political Science, Definitions of Political Science, Nature of Political Science, Scope of Political Science, Significance (or) Importance of Politica Science

Chapter 2 State
Meaning and definition of State, State and Its Essential elements – Population, Territory, Government and Sovereignty, Other elements of the State – International recognition, permanence, general obedience, and popular will, Relationship between State and Society, DIfferences between Stat. and Society, Relationship between State and Association, Differences between State and Association, Relationship between State and Government, Differences between State and Government

Chapter 3 Nationalism
Meaning and definitions of Nation, Meaning and definition of Nationality, Essential Elements of Nationality, Nationalism, Differences between Nation and State, Differences between Nation and Nationality, National self-determination, India is a Nation State, Uni-national State, Multi-national State, Connotations of Nationality, Different phases of Nationalism, Merits and Demerits of Nationalism

Chapter 4 Law
Meaning of Law, Definitions of Law, Features of Law, Sources of Law, Classification of Law, Law and Morality Relationship, Law and Morality Differences, Relation between Law and Liberty, Differences between Law and Liberty, Rule of Law

Chapter 5 Liberty and Equality
Introduction to Liberty, Meaning of Liberty, Definitions of Liberty, Aspects of Liberty, Characteristics of Liberty, Types of Liberty, Safeguards of Liberty, Elements Threatening of Individual Liberty, Introduction to Equality, Meaning of Equality, Aspects of Equality, Essential features of Equality, Types of Equality, Various obstacles to Equality, Relation between Liberty and Equality

Chapter 6 Rights and Responsibilities
Introduction, Meaning and Definition of Rights, Features of Rights, Classification of Rights, Important Civil Rights, Important Political Rights, Important Economic Rights, Fundamental Rights, Safeguards of Rights, Human Rights, Features of Human Rights, Responsibilities, Types of Responsibilities, Important Responsibilities of a citizen, Relationship between Rights and Responsibilities

Chapter 7 Justice
Introduction, Definitions, Major Concepts of Justice, Connotations of Justice, Aspects of Justice, Evolution of Justice, Sources of Justice, Types of Justice, Social Justice, Achievement of Social Justice

Chapter 8 Citizenship
Introduction, Definition, Aliens, Methods of Acquiring Citizenship, Loss of Citizenship, Qualities of good Citizen, Hindrances to good Citizenship, Suggestions for overcoming the hindrances to good Citizenship, Types of Citizenship, Global or Universal Citizenship, Significance of Citizenship

Chapter 9 Democracy
Introduction, Origin, Evolution, and growth of Democracy, Features of Democracy, Types of Democracy, Merits of Democracy, Demerits of Democracy, Essential conditions to the success of Democracy, Importance of Democracy, Working of Democracy in India, Devices of Direct Democracy, Future of Democracy in India

Chapter 10 Secularism
Introduction, Origin of Secularism, Meaning and definitions of Secularism, Interpretations on Secularism, Types of Secularism, Factors that led to the spread of Secularism, Conceptions of Secularism, Dimensions of Secularism, Secularism Vs Theocracy, Meaning of Theocracy, Differences between Secular State and Theocratic State, Merits of Secularism, Meaning of Secular State, Features of Secular State, Importance of Secular State, Secularism in the Indian context, Suggestions for making India as a Secular State

Chapter 11 Constitutions
Introduction, Definitions of Constitution, Essential features of the Constitution, Classification of Constitution

Chapter 12 Government
Introduction, Meaning of Government, Classification of Governments, Unitary Government, Federal Government, Distinction between Unitary and Federal Governments, Parliamentary Government, Presidential Government, Differences between Parliamentary and Presidential Governments, Theory of Separation of Powers, Organs of Government, Legislature, Executive, Judiciary

We hope that this Telangana & Andhra Pradesh BIEAP TS AP Intermediate Inter 1st Year Civics Study Material Textbook Solutions Guide PDF Free Download 2022-2023 in English Medium and Telugu Medium helps the student to come out successful with flying colors in this examination. This Jr Inter 1st Year Civics Study Material will help students to gain the right knowledge to tackle any type of questions that can be asked during the exams.

Andhra Pradesh BIEAP AP Inter 1st Year Zoology Study Material Lesson 8 Ecology and Environment Textbook Questions and Answers.

AP Inter 1st Year Zoology Study Material Lesson 8 Ecology and Environment

Very Short Answer Type Questions

Question 1.
Define the term “ecology” and its branches.
Answer:
The word ‘ecology’ was derived from the Greek terms (‘Oikos house and ‘logos’ – ‘study’) and it can be defined as “the study of the relationship of organisms with their environment”.

Question 2.
What is an ecological population?
Answer:
A population is a group of organisms of the same species living in a specific area at a specific time.

Question 3.
Define a community.
Answer:
It is an association of the interacting members of populations of different autotrophic and heterotrophic species in a particular area.

Question 4.
What is an ecosystem?
Answer:
An ecosystem is a functional unit of the biosphere in which members of the community interact among themselves and with the surrounding environment.

Question 5.
Distinguish between ecosystem and biome.
Answer:

Question 6.
What is a biome? Name any two biomes you studied.
Answer:
A ‘biome’ is a large community of plants and animals that occupies a vast region.
Ex: Tropical rain forest, desert, tundra (terrestrial biomes) Freshwater biomes, marine biome (aquatic biomes).

Question 7.
What is meant by ecosphere?
Answer:
It is the part of the Earth that supports ‘life’. It extends several kilometers above the Earth’s surface into the atmosphere and extends several kilometers below the ocean’s surface.

Question 8.
Explain the difference between the ‘nich’ of an organism and its ‘habitat’.
Answer:

Question 9.
A population has more genetically similar organisms than a biotic community. Justify the statement.
Answer:
A population is a group of organisms of the same species, living in a specific area at a specific time.
Ex: The fish belongs to the species Catla. catla living at a given time.

Question 10.
How do the fish living in Antarctic waters manage to keep their body fluids from freezing?
Answer:
During the course of millions of years of their existence, many species (fish) would have evolved a relatively constant internal (within body) environment so it permits all biochemical reactions and physiological reactions to proceed with maximal efficiency and thus, enhance the overall “fitness” of the species.

Question 11.
How does your body solve the problem of altitude sickness, when you ascend tall mountains?
Answer:
The body compensates for low oxygen availability by increasing red blood cell production and increasing the rate of breathing.

Question 12.
What is the effect of light on body pigmentation?
Answer:
Light influences the colour of the skin. The animals which live in the regions of low intensity of light have less pigmentation than the animals exposed to light.

Question 13.
Distinguish the terms phototaxis and photokinesis.
Answer:
Phototaxis is the oriented locomotion of an organism towards or away from the direction of light.
Ex: As seen in Euglena
Photokinesis is the influence of light on the non-directional movement of organisms.
Ex: Mussel crab

Question 14.
What are circadian rhythms?
Answer:
Biological rhythms that occur in a time period of 24 hours are called circadian rhythms.

Question 15.
What is photoperiodism?
Answer:
The response of organisms to the photoperiod is called photoperiodism.
Ex: Reproduction of flowers, migration of birds.

Question 16.
Distinguish between photoperiod and critical photoperiod.
Answer:
Photoperiod: The duration of light hours is known as a photoperiod.
Critical photoperiod: The specific day length which is essential for the initiation of seasonal events is called critical photoperiod.

Question 17.
Mention the advantages of some UV rays to us.
Answer:

• UV radiation kills the microorganisms present on the body surface of animals.
• UV radiation helps in the conversion of sterols present in the skin into vitamin D in mammals.

Question 18.
What is cyclomorphosis? Explain its importance in Daphnia.
Answer:
The cyclic seasonal morphological variations among certain organisms are called “Cyclomorphosis”. In the case of Daphnia, it is an adaptation to “stabilize the movement” in water and can “resist the water currents better” to stay in the water rich in food materials.

Question 19.
What are ‘regulators’?
Answer:
Organisms that are able to maintain homeostasis by physiological means which ensure constant body temperature, and constant osmotic concentration are called, “regulators”.
Ex: Mammals, Birds

Question 20.
What are conformers?
Answer:
Living organisms that cannot maintain 3 constant internal environments are described as “conformers”.

Question 21.
Define commensalism. Give one example.
Answer:
This is the interaction in which one species benefits and the other is neither harmed nor benefited.
Ex: Barnacles growing on the back of a whale benefit while the whale derives no noticeable benefit.

Question 22.
Define mutualism. Give one example.
Answer:
This is the interaction that benefits both the interacting species.
Ex: Lichens represent an intimate mutualistic relationship between a fungus and photosynthesizing algae.

Question 23.
Define amensalism. Give one example.
Answer:
Amensalism is an interaction in which one species is harmed whereas the other one is unaffected.

Question 24.
What is meant by interspecific competition? Give one example.
Answer:
A process in which the fitness of one species is significantly lower in the presence of another species is called interspecific competition.
Ex: Competition between visiting flamingos and resident fishes in shallow South American lakes.

Question 25.
What is camouflage? Give its significance.
Answer:
Some species of insects and frogs are cryptically coloured to avoid being detected easily by the predator. This phenomenon is called “Camouflage”.

Question 26.
What is Gause’s principle? When does it applicable?
Answer:
When the resources are limited, the competitively superior species will eventually eliminate the other species. It is relatively easy to demonstrate in laboratory experiments.

Question 27.
Name the association that exists in mycorrhiza.
Answer:
The association that exists in mycorrhiza is called “Mutualism”.

Question 28.
Distinguish between lotic and lentic habitats.
Answer:

Question 29.
What is a zone of compensation in an aquatic ecosystem?
Answer:
The imaginary line that separates the limnetic zone from the profundal zone in a lake is called the zone of compensation (or) compensation point.

Question 30.
Distinguish between phytoplankton and zooplankton.
Answer:

Question 31.
Distinguish between neuston and nekton.
Answer:

Question 32.
What is periphyton?
Answer:
The animals that are attached to/creeping on the aquatic plants are called “periphyton”.
Ex: Water snails, hydras, nymphs of insects, etc.

Question 33.
Write three examples of man-made ecosystems.
Answer:
Cropland ecosystems, Aquaculture ponds, Aquaria.

Question 34.
What is meant by osmotrophic nutrition?
Answer:
The state of pre-digested food material through the body surface is known as osmotrophic nutrition.

Question 35.
Explaining the process of “leaching”.
Answer:
When the water-soluble inorganic nutrients go down into the soil and get precipitated as unavailable salts that entire process is called “leaching”.

Question 36.
What is PAR?
Answer:
PAR means “Photosynthetically Active Radiation”.

Question 37.
What is the percentage of PAR, in the incident solar radiation?
Answer:
Of the incident solar radiation, less than 50% of it is PAR.

Question 38.
Define entropy.
Answer:
As per the second law of thermodynamics, the energy dispersed is in the form of unavailable heat energy and constitutes entropy.

Question 39.
What is a standing crop?
Answer:
Each trophic level has a certain mass of living material at a particular time and it is called the “Standing crop”.

Question 40.
Explain the terms GPP and NPP.
Answer:
GPP means Gross primary productivity.
NPP means Net primary productivity.

Question 41.
Distinguish between upright and inverted ecological pyramids.
Answer:

Question 42.
Distinguish between litter and detritus.
Answer:
Litter: Litter is just like manure that is formed by dead (Either plant (or) Animal clusters) organic matter. It is the primary food source in the detritus food chain.
Detritus: It is a decaying organic matter being decomposed into detritivores organisms.

Question 43.
Distinguish between primary and secondary productivity.
Answer:

Question 44.
Which air pollutants are chiefly responsible for acid rains?
Answer:
Sulphur dioxide (SO₂) and nitrogen oxides are the major causes of acid rain.

Question 45.
What is BOD?
Answer:
BOD means Biological Oxygen Demand. It is a measure of the content of biologically degradable substances in sewage.

Question 46.
What is biological magnification?
Answer:
An increase in the concentration of the pollutant (or) toxicant at successive trophic levels in an aquatic food chain is called ‘Bio-magnification’.

Question 47.
Why are incinerators used in hospitals?
Answer:
Disposal of hospital wastes that contain disinfectants, harmful chemicals, and also pathogenic micro-organisms incinerators are used in hospitals.

Short Answer Type Questions

Question 1.
Considering the benefits of a constant internal environment to the organism we tend to ask ourselves why the conformers had not evolved to become regulators.
Answer:
Thermoregulation is energetically expensive for many organisms. This is particularly true in small animals like shrews and hummingbirds. Heat loss or heat gain is a function of the surface area. Since small animals have a larger surface area relative to their volume, they tend to lose body heat very fast when it is cold outside. Then they have to spend much energy to generate body heat through metabolism. This is the main reason why very small animals are rarely found in polar regions. During the course of evolution, the costs and benefits of maintaining a constant internal environment are taken into consideration. Some species have evolved the ability to regulate, but only over a limited range of environmental conditions, beyond which they simply conform.

Question 2.
The individuals who have fallen through the ice and been submerged under cold water for long periods can sometimes be revived – explain.
Answer:
Temperature variations occur with seasonal changes. These differences in the temperature form thermal layers in water. Water shows maximum density at 4°C decrease its density. Generally, during the winter season the surface water cools down in the upper water phases in the temperature reaches 0°C. below the upper icy layer, the cool water occupies the lake. The aquatic animals continue their life below the icy layer at lower temperatures the activity of bacteria and the rate of oxygen consumption by aquatic animals decrease. Hence organisms can survive below the frozen (icy) upper water without being subject to hypoxia.

Question 3.
What is summer stratification? Explain.
Answer:
During summer in temperate lakes, the density of the surface water decreases because of an increase in its temperature (21-25°C). This ‘uppermost warm layer’ of a lake is called the epilimnion. Below the epilimnion, there is a zone in which the temperature decreases at the rate of 1°C per meter in-depth, and it is called thermocline or metalimnion. The bottom layer is the hypolimnion, where water is relatively cool, stagnant, and with low oxygen content (due to the absence of photosynthetic activity).

During autumn (also called fall). The epilimnion cools down, and the surface water becomes heavy when the temperature is 4°C and sinks to the bottom of the lake overturns bringing about a ‘uniform temperature’ in lakes during that period, this circulation during the autumn is known as fall. The upper oxygen-rich water reaches the hypolimnion and the nutrient-rich bottom water comes to the Surface. Thus there is a uniform distribution of nutrients and oxygen in the lake.

Question 4.
What is the significance of stratification in lakes?
Answer:
Temperature variations occur with seasonal changes in temperature regions. These differences in the temperature form thermal layers in water. These phenomena are called thermal stratification.

During autumn (also called fall), the epilimnion cools down and the surface water becomes heavy when the temperature is 4°C and sinks to the bottom of the lake. Overturns bring about uniform temperatures in lakes during that period. This circulation during autumn is known as the fall or autumn overturn. The upper oxygen-rich water reaches the hypolimnion and the nutrient-rich bottom water comes to the surface. Thus there is a uniform distribution of nutrients and oxygen in the lake. In the spring season the temperatures start rising when it reaches 4°C, the water becomes more dense and heavy and sinks to the bottom, taking oxygen-rich sinks down and bottom nutrient-rich water reaches the surface.

Question 5.
Explain Vant’ Hoff’s rule.
Answer:
Van’t Hoff, a Nobel Laureate in thermo chemistry proposed that, with the increase of every 10°C, the rate of metabolic activities doubles. This rule is referred to as Van’t Hoff’s rule. Van’t Hoffs rule can also be stated in reverse saying that the reaction rate is halved with the decrease of every 10°C. The effect of temperature on the rate of a reaction is expressed in terms of the temperature coefficient of the Q10 value. Q10 values are estimated by taking the ratio between the rate of a reaction at X°C and the rate of reaction at (X – 10°C). In the living systems, the Q10 value is about 2.0. If the Q10 value is 2.0, it means, for every 10°C increase, the rate of metabolism doubles.

Question 6.
Unlike mammals, reptiles cannot tolerate environmental fluctuations in temperature. How do they adapt to survive in desert conditions?
Answer:
Some organisms show behavioural responses to cope with variations in their environment. Desert lizards manage to keep their body temperature fairly constant by behavioural means. They ‘bask’ (staying in the warmth of sunlight) in the sun and absorb heat when their body temperature drops below the comfort zone, but move into the shade when the temperature starts increasing. Some species are capable of burrowing into the soil to escape from the excessive heat above the ground level.

Question 7.
How do terrestrial animals protect themselves from the danger of being dehydration of bodies?
Answer:
In the absence of an external source of water, the kangaroo rat of the North American deserts is capable of meeting all its water requirements through oxidation of its internal fat (in which water is a by-product – of metabolic water). It also has the ability to concentrate its urine, so that minimal volume of water is lost in the process of removal of its excretory products.

Question 8.
How do marine animals adapt to hypertonic seawater?
Answer:
To overcome the problem of water loss, marine fishes have glomerular kidneys with less number of nephrons. Such kidneys minimize the loss of water through urine. To compensate for water loss marine fish drink more water and along with this water, salts are added to the body fluids and disturb the internal equilibrium. To maintain salt balance (salt homeostasis) in the body they have salt-secreting chloride cells in their gills. Marine birds like seagulls and penguins eliminate salts in the form of salty fluid that drips through their nostrils. In turtles, the ducts of chloride-secreting glands open near the eyes. Some cartilaginous fishes retain urea and trimethylamine oxide (TMO) in their blood to keep the body fluids isotonic to the seawater and avoid dehydration of the body due to exosmosis.

Question 9.
Discuss the various type of adaptations in freshwater animals.
Answer:
Animals living in fresh waters have to tackle the problem of endosmosis. The osmotic pressure of freshwater is very low and that of the body fluids of freshwater organisms is much higher. So water tends to enter into bodies by endosmosis. To maintain the balance of water in the bodies, the freshwater organisms acquired several adaptations such as contractile vacuoles in the freshwater protozoans, and large glomerular kidneys in fishes, etc., They send out large quantities of urine along which some salts are also lost. To compensate for the ‘salt loss’ through urine freshwater fishes have ‘salt absorbing chloride cells’ in their gills.

The major problem in freshwater ponds is in summer most of the ponds dry up. To overcome this problem most of the freshwater protists undergo encystment. The freshwater sponges produce asexual reproductive bodies, called gemmules, to tide over the unfavourable conditions of the summer. The African lungfish Protopterus burrows into the mud and forms a gelatinous cocoon around it, to survive, in summer.

Question 10.
Compare the adaptations of animals with fresh water and seawater mode of life.
Answer:

Question 11.
Distinguish between euryhaline and stenohaline animals.
Answer:

Question 12.
Many tribes living at high altitudes in the Himalayas normally have higher red blood cell count (or) total haemoglobin than the people living in the plains. Explain?
Answer:
Some organisms possess adaptations that are physiological and allow them to respond quickly to a stressful situation. If you had ever been to any high-altitude place (e.g. > 3,500 M Rohtang pass near Manali and Manasarovar, in Tibet) you must have experienced what is called altitude sickness. Its symptoms include nausea (vomiting sense), fatigue (tiredness), and heart palpitations (abnormality in heartbeat). This is because, in the low atmospheric pressure of high altitudes, the body does not get enough oxygen. But, you gradually get acclimatized and overcome the altitude sickness. How did your body solve this problem? The body compensates for low oxygen availability by increasing red blood cell production and increasing the rate of breathing.

Question 13.
An orchid plant is growing on the branch of the mango tree. How do you describe this interaction between the orchid and mango tree?
Answer:
An orchid growing as an epiphyte on a mango branch gets the benefit of exposure to light, while the mango tree does not drive any noticeable benefit. So in this interaction, one species (arched) get benefitted the other (Mango) is neither armed nor benefitted. So the interactions between orchids and mango trees are commensalism.

Question 14.
Predation is not an association. Support the statement.
Answer:
Predation is not an association (it is a feeding strategy), it is an interaction between two different species. The predator gets benefits at the cost of the prey. Besides acting as) pipelines for energy transfer across trophic levels predators play other important roles. They keep the prey populations under control. In the absence of predators, the prey species could achieve very high population densities and cause instability in the ecosystem.

Question 15.
What is the biological principle behind the biological control method of managing pest insects?
Answer:
The prickly pear cactus introduced in Australia in the early 1920s caused havoc by spreading rapidly into millions of hectares of Rangel and (vast natural grasslands). Finally, the invasive cactus was brought under control only after a cactus-feeding predator (a moth) was introduced into the country. Biological control methods adopted in agricultural pest control are based on the ability of the predators to regulate prey populations.

Question 16.
Discuss competitive release.
Answer:
Another evidence for the occurrence of competition in nature comes from what is called competitive releases. Competitive release occurs when one of the two competing species is removed from an area, thereby releasing the remaining species from one of the factors that limited its distributional range dramatically when the competing species is experimentally removed. This is due to the phenomenon called competitive release, Connells field experiments showed that on the rocky sea coasts of Scotland the larger and competitively superior barnacle Balanus dominates the intertidal area, and excludes the smaller barnacle chathamalus from that zone. When the dominant one is experimentally removed, the population of the smaller one’s increases. In general, herbivores and plants appear to be more adversely affected by competition than carnivores.

Question 17.
Write a short note on the parasitic adaptations.
Answer:
In order to lead successful parasitic life, parasites evolved special adaptations such as:

• Loss of sense organs (which are not necessary for most parasites).
• Presence of adhesive organs such as suckers, and hooks to cling to the host’s body parts.
• Loss of digestive system and presence of high reproductive capacity.
• The life cycles of parasites are often complex, involving one or two intermediate hosts or vectors to facilitate the parasitization of their primary hosts.

Examples:

• The human liver fluke depends on two intermediates (secondary) hosts (a snail and a fish) to complete its life cycle.
• The malaria parasite needs a vector (mosquito) to spread to other hosts. The majority of the parasites harm the host: they may reduce the survival, growth, and reproduction of the host and reduce its population density. They might render the host more vulnerable to predation by making it physically weak.

Question 18.
Explain brood parasitism with a suitable example.
Answer:
Certain birds are fascinating examples of a special type of parasitism, in which the parasitic bird lays its eggs in the nest of its host and lets/allows the host incubates them. During the course of evolution, the eggs of the parasitic bird have evolved to resemble the host’s egg in size and colour to reduce the chances of the host bird detecting the foreign eggs and ejecting them from the nest.

Question 19.
How do predators act as biological control?
Answer:
The prickly pears cactus introduced in Australia in the early 1920s caused havoc by spreading rapidly into millions of hectares of Rangel and (vast natural grasslands) Finally, the invasive cactus was brought under control only after a cactus-feeding predator (a moth) was introduced into the country. Biological control methods adopted in agricultural pest control are based on the ability of the predators to regulate prey populations.

Question 20.
Write notes on the structure and functioning of an ecosystem.
Answer:
‘An ecosystem’ is a functional unit of nature, where living organisms interact among themselves and also with the surrounding physical environment.

Ecosystem varies greatly in size from a small pond to a large forest or a sea. Many ecologists regard the entire biosphere as a global ecosystem as a composite of all local ecosystems on Earth. Since this system is too big and complex to be studied at one time it is convenient to divide it into two basic categories, namely natural and artificial. The natural ecosystems include aquatic ecosystems of water and terrestrial ecosystems of the land. Both types of natural and artificial ecosystems have several subdivisions.

The Natural Ecosystem: These are naturally occurring ecosystems and there is no role of humans in the formation of such types of ecosystems. These are categorized mainly into two types – aquatic and terrestrial ecosystems. These are man-made ecosystems such as agricultural or agroecosystems. They include cropland ecosystems, aquaculture ponds, and aquaria.

Question 21.
Explain the different types of aquatic ecosystems.
Answer:
Based on the salinity of water, three types of aquatic ecosystems are identified marine, fresh water, and estuarine.

• The marine ecosystem: It is the largest of all the aquatic ecosystems. It is the most stable ecosystem.
• Estuarine ecosystem: Estuary is the zone where the river joins the sea, and seawater ascends up into the river twice a day (effect of high tides and low tides). The salinity of water in an estuary also depends on the seasons. During the rainy season outflow of river water makes the estuary saline and the opposite occurs during the summer. Estuarine organisms are capable of withstanding the fluctuations in salinity.
• The freshwater ecosystem: The freshwater ecosystem is the smallest aquatic ecosystem. It includes rivers, lakes, ponds, etc., It is divided into two groups the lentic and lotic. The still water bodies like ponds, lakes reservoirs, etc., fall under the category of lentic ecosystems, whereas streams, rivers, and flowing water bodies are called lotic ecosystems. The communities of the above two types are called lentic and lotic communities respectively. The study of freshwater ecosystems is called limnology.

Question 22.
Explain the different types of terrestrial ecosystems.
Answer:
The ecosystems of land are known as terrestrial ecosystems. Some examples of terrestrial ecosystems are the forest, grass, and desert.

• The forest ecosystem: The two important types of forests seen in India are tropical rain forests and tropical deciduous forests.
• The grassland ecosystems: These are present in the Himalayan region of India. They occupy large areas of sandy and saline soils in western Rajasthan.
• Desert ecosystem: The areas having less than 25 cm of rainfall per year are called deserts. They have characteristic flora and fauna. The deserts can be divided into two types – hot type and cold type deserts, the desert in Rajasthan is an example of the hot type of desert. Cold-type desert is seen in Ladakh.

Question 23.
Discuss the main reason for the low productivity of the ocean.
Answer:
The Primary productivity is very low in the ocean ecosystem compared with the terrestrial ecosystem.

Unlike terrestrial ecosystems, the majority of primary production in the ocean is performed by feel living microscopic organisms called Phytoplankton, large autotrophs such as the seagrasses and macroalgae or seaweeds are generally confined to the littoral zone.

The sunlight zone of the ocean is called the photic zone or euphotic zone, it is a thin layer upto 10 to 100 m near the Ocean’s surface where there is sufficient light for photosynthesis to occur. Light is attenuated down the water column by its absorption or scattering by the water itself. Net photosynthesis in the water column is determined by the interaction between the photic zone and the mixed layer. In the deep water of the ocean (Demersal) there is no light penetration for photosynthesis.

Another factor relatively recently discovered to play a significant role in oceanic primary production is the micronutrient iron. The factors limiting primary production in the ocean are also very different from those on land. However, the availability of light, the source of energy for photosynthesis, and mineral nutrients, building the blocks for new growth, play a crucial role in regulating primary production in the ocean.

Question 24.
Explain the terms saprotrophs detritivores and mineralizers.
Answer:
Saprotrophs are microorganisms such as fungi and bacteria which live on dead organic matter. Detritivores ingest small fragments of decomposing organic materials, termed detritus mineralizers affect the mineralization of humans.

Question 25.
Define decomposition and describe the process and products of decomposition.
Answer:
When organisms die, their bodies and the waste materials passed from the bodies of living organisms form a source of energy and nutrient for the decomposer organisms like saprotrophs detritivores, and mineralizers. Saprotrophs absorb substances through the general body surface of the dead bodies. Detritivores ingest detritus as food. Mineralized mineralize humus these decomposers are referred to as micro consumers of the ecosystem. The decomposition of organic matter includes three phases. In the first phase, particulate detritus is formed by the action of saprotrophs. The second stage is the rapid action of saprotrophs and detritivores to convert detritus into humic substances. The third process is the slower mineralization of the hummus.

Decomposers also play an important role in an ecosystem by converting complex molecules of dead organisms into simpler and reusable molecules. The breakdown products of the dead organisms and waste materials are recycled in the ecosystem and are made available to the producers. The producers cannot continue to exist forever in the absence of the decomposers (as minerals are not returned to the environment).

Question 26.
Write a note on DFC. Give its significance in a terrestrial ecosystem.
Answer:
The detritus food chain (DFC) begins with dead organic matter (such as leaf litter, and bodies of dead organisms). It is made up of decomposers which are heterotrophic organisms ‘mainly’ the fungi’ and ‘bacteria’. They meet their energy and nutrient requirements by degrading dead organic matter to detritus. These are also known as saprotrophs.

Decomposers secrete digestive enzymes that break down dead and waste materials (such as feces i) into simple absorbable substances. Some examples of detritus food chains are:

• Detritus – Earthworm – Frogs – Snakes
• Dead animals – Flies and maggots – Frogs – Snakes

In an aquatic ecosystem. GFC is the major conduit for the energy flow. As against this, in a terrestrial ecosystem, a much larger fraction of energy flows through the detritus food chain than through the GFC. The Detritus food chain may be connected with the grazing food chain at some levels. Some of the organisms of DFC may form the prey of the GFC animals. For example, in the detritus food chain given above, the earthworms of the DFC may become the food of the birds of the GFC. It is to be understood that food chains are not ‘isolated1 always.

Question 27.
What is primary productivity? Give a brief description of the factors that affect primary productivity.
Answer:
Primary productivity is defined as the amount of biomass or organic matter produced per unit area over a period of time by plants, during photosynthesis. It can be divided into Gross Primary Productivity (GPP) and Net Primary Productivity (NPP).
(a) Gross Primary Productivity: Of an ecosystem is the rate of production of organic matter
during photosynthesis. A considerable amount of GPP is utilized by plants for their catabolic process (respiration).
(b) Net Primary Productivity: Gross Primary Productivity minus respiratory loss (R), is the Net Primary Productivity (NPP). On average about 20-25 percent of GPP is used for catabolic (respiratory) activity.
GPP – R = NPP
The Net Primary productivity is the biomass available for the consumption of the heterotrophs (herbivores and decomposers).

Question 28.
Define ecological pyramids and describe with examples, pyramids of numbers and biomass.
Answer:
It is a graphical representation of the trophic structure and function of an ecosystem. The base of each pyramid represents the producers of the first trophic level, while the apex represents the tertiary or top-level/top-order consumers. The three types of ecological pyramids that are usually studied are (a) pyramid of numbers (b) pyramid of biomass and (c) pyramid of energy. These pyramids were first represented by Elton, hence the name ELTONIANpyramids/Ecological pyramids.

Any calculations of energy content, biomass, or numbers have to include all organisms at that trophic level. No generalizations we make will be true if we take only a few individuals of any trophic level into account. In most ecosystems, all the pyramids – of numbers, energy, and biomass are uprights. i.e., producers are more in number and biomass than the herbivores, and herbivores are more in number and biomass than the carnivores. Also, energy (available) at a lower trophic level is always more than that at a higher level.

There are exceptions to this generalization. In the case of a parasitic food chain, the pyramid of numbers is inverted. A large tree (single producer) may support many herbivores like squirrels and fruit-eating birds. On these herbivores, many ectoparasites such as ticks, mites, and lice (secondary consumers) may live. These secondary consumers may support many more top-level consumers and also the hyper-parasites. Thus in each trophic level from the bottom to the top, the numbers of organisms increase and form an ‘inverted pyramid’ of numbers.

The pyramid of biomass in the sea is also generally inverted because the biomass of fishes far exceeds that of phytoplankton.

Question 29.
What are the deleterious effects of depletion of ozone in the stratosphere?
Answer:
The depletion of ozone is particularly marked over the Antarctic region. This has resulted in the formation of a large area of thinned ozone layer commonly called the ‘ozone hole.

UV radiation with wavelengths shorter than that of UV-B is almost completely absorbed by Earth’s atmosphere, provided that the ozone layer is intact. But IJV-B damages DNA and may induce mutations. It causes aging of the skin, damage to skin cells, and various types of skin cancers. In the human eye, the cornea absorbs UV-B radiation, and a high dose of UV-B causes inflammation of the cornea called snow-blindness, cataract, etc., such exposure may permanently damage the cornea.

Question 30.
Describe the ‘Green House’ Effect.
Answer:
The term Green House effect’ has been derived from a phenomenon that occurs in a greenhouse. The greenhouse is a small glasshouse and is used for growing plants, especially during winter. In a greenhouse, the glass panel allows the passage of light into it but does not allow heat to escape (as it is reflected back). Therefore, the greenhouse warms up, very much like inside a car that has been parked in the sun for a few hours.

The greenhouse effect is a naturally occurring phenomenon that is responsible for heating the Earth’s surface and atmosphere. It would be surprising to know that without the greenhouse effect the average temperature of the Earth’s surface would have been chilly – 18°C rather than the present average of 15°C.

When sunlight reaches the outermost layer of the atmosphere, clouds and gases reflect about one-fourth of the incoming solar radiation and absorb some of it. Almost half of the incoming solar radiation falls on the Earth’s surface and heats it up. While a small proportion is reflected back.

Question 31.
Discuss briefly the following:
(a) Greenhouse gases
(b) Noise pollution
(c) Organic farming
(d) Municipal solid wastes
Answer:
(a) Greenhouse gases: The Earth’s surface re-emits heat in the form of infrared radiation but part of this does not escape into space as atmospheric gases (e.g. carbon dioxide, methane, etc.) absorb a major fraction of it. The molecules of these gases radiate heat energy, a major part of which again comes back to the Earth’s surface, thus heating it up once again. The above-mentioned gases- Carbon dioxide and methane are commonly known as greenhouse gases.

(b) Noise pollution: Undesirably high sounds constitute noise pollution. Sound is measured in units called decibels. The human ear is sensitive to sounds ranging from 0 to 180 dB. 0 dB is the threshold limit of hearing and 120 dB is the threshold limit for the sensation of pain in the ear. Any noise above 120 dB is considered to be noise pollution. Brief exposure to the extremely high sound level. 150 dB or more generated by jet planes while taking off may damage eardrums causing permanent hearing impairment. Even long-term exposure to a relatively higher level of noise in cities may also cause hearing impairment. Noise also causes auditory fatigue, anxiety, sleeplessness/msommaj, increased heartbeat, and altered breathing pattern thus causing considerable stress to humans.

(c) Organic farming: Integrated organic farming is a zero waste procedure, where the recycling of waste products is efficiently carried out. This allows the maximum utilization of resources and increases the efficiency of production. A method practiced by Ramesh Chandra Dagar, all these processes support one another and allow an extremely economical and sustainable venture. Natural – biogas generated in the process can be used for meeting the energy needs of the farm. Enthusiastic about spreading information and helping in the practice of integrated organic farming, Dagar has created the Haryana Kisan welfare club.

(d) Municipal Solid waste: Anything (substance/material/articles/goods) that is thrown out as waste in solid form is referred to as solid waste. The municipal solid wastes generally consist of paper, food wastes, plastics, glass, metals, rubber, leather, textile, etc., The wastes are burnt to reduce the volume of the waste. As a substitute for open-burning dumps, sanitary landfills are adopted. There is a danger of seepage of chemicals and pollutants from these landfills, which may contaminate the underground water resources.

Question 32.
Discuss the causes and effects of global warming. What measures need to be taken to control ‘Global warming’?
Answer:
An increase in the level of greenhouse gases has led to considerable heating of the “Earth leading to global warming. During the past century, the temperature of the earth has increased by 0.6°C most of it during the last three decades. Scientists believe that this rise in temperature is leading to severe changes in the environment. Global warming is causing climatic changes (e.g. as El Nino effect) and is also responsible for the melting of polar ice caps and other snow caps of mountains such as the Himalayas. Over many years, this will result in a rise in sea levels, all over the world, that can submerge many coastal areas. The total spectrum of changes that global warming can bring about is a subject that is still under active research.

Global warming: Control measures

• The measures include cutting down the use of fossil fuels.
• Improving the efficiency of energy usage.
• Planting trees and avoiding deforestation.

Question 33.
Write critical notes on the following:
(a) Eutrophication
(b) Biological magnification
Answer:
(a) Eutrophication: Natural ageing of a lake by nutrient enrichment of its water is known as eutrophication. In a young lake, the water is cold and clear supporting little life. Gradually nutrients such as nitrates and phosphates are carried into the lake via streams, in course of time. This encourages the growth of aquatic algae and other plants. Consequently, animal life proliferates and organic matter gets deposited on the bottom of the lake. Over centuries, as silt and organic debris pile up the lake grows shallower and warmer. As a result, the aquatic organisms thriving in the cold environment are gradually replaced by warm-water organisms. Marsh plants appear by taking root in the shallow regions of the lake. Eventually, the lake gives way to large masses of floating plants (bog) and is finally converted into land.

(b) Biological magnification: Increase in the concentration of the pollutant or toxicant at successive trophic levels in an aquatic food chain is called biological magnification or Bio-magnification. This happens in the instance where a toxic substance accumulated by an organism is not metabolized or excreted and thus passes on to the next higher trophic level. This phenomenon is well known regarding DDT and mercury pollution.

As shown in the above example, the concentration of DDT is increased at successive trophic levels. Starting at a very low concentration of 0.003 PPb (PPb part per billion) in water, which ultimately reached an alarmingly high concentration of 25 ppm (ppm = parts per million) in fish-eating birds through biomagnification. High concentrations of DDT disturb calcium metabolism in birds, which causes thinning of eggshells and their premature breaking, eventually causing a decline in bird populations.

(c) Groundwater depletion and ways for its replenishment: Sewage arising from homes and hospitals may contain undesirable pathogenic microorganisms. If it is released untreated into water courses, there is a likelihood of an outbreak of serious diseases, such as dysentery, typhoid, jaundice, cholera, etc.

Untreated industrial effluents released into water bodies pollute most of the rivers, freshwater streams, etc. Effluents contain a wide variety of both inorganic and organic pollutants such as oils, greases, plastics, metallic wastes, suspended solids, and tonics. Most of them are non-degradable. Arsenic, Cadmium, Copper, Chromium, Mercury, Zinc, and Nickel are the common heavy metals discharged from industries.

Effects: Organic substances present in the water deplete the dissolved oxygen content in water by increasing the BOD (Biological Oxygen Demand) and COD (Chemical Oxygen Demand). Most of the inorganic substances render the water unit for drinking.

Removal of dissolved salts such as nitrates, phosphates, and other nutrients and toxic metal ions and organic compounds is much more difficult. Domestic sewage primarily contains biodegradable organic matter, which will be readily decomposed by the action of bacteria and other microorganisms.

Water-logging and soil salinity: Irrigation without proper drainage of water leads to water logging in the soil. Besides affecting the crops, water logging draws salt to the surface of the soil (salinization of the topsoil). The salt then is deposited as a thin crust on the land surface or starts collecting at the roots of the plants. This increased salt content is inimical (unfavourable) to the growth of crops and is extremely damaging to agriculture. Water logging and soil salinity are some of the problems that have come in the wake of the Green Revolution.

Long Answer Type Questions

Question 1.
Write an essay on temperature as an ecological factor.
Answer:
Temperature is a measure of the intensity of heat. The temperature on land or in water is not uniform. On land, the temperature variations are more pronounced when compared to the aquatic medium because land absorbs or loses heat much more quickly than water. The temperature on land depends on seasons and the geographical area on this planet. Temperature decreases progressively when we move from the equator to the poles. Altitude also causes variations in temperature. For instance, the temperature decreases gradually as we move to the top of the mountains.

Biological effects of Temperature:
Temperature Tolerance: A few organisms can tolerate and thrive in a wide range of temperatures they are called eurythermal, but, a vast majority of organisms are restricted to a narrow range of temperatures such organisms are called stenothermal. The levels of thermal tolerance of different species determine their geographical distribution.

Temperature and Metabolism: Temperature affects the working of enzymes and through it, the basal metabolism, and other physiological functions of the organism. The temperature at which the metabolic activities occur at the climax level is called the optimum temperature. The lowest temperature at which an organism can live indefinitely is called minimum effective temperature. It an animal or plant is subjected to a temperature below the minimum effective limit, enters into a condition of inactivity called a chill coma. The metabolic rate increases with the rise of temperature from the minimum effective temperature to the optimum temperature.

The maximum temperature at which a species can live indefinitely in an active state is called maximum effective temperature, the animals enter into a ‘heat coma’. The maximum temperature varies much in different animals.

Vant Hoffs’s rule: Vant Hoff, a Nobel Laureate the thermochemistry proposed that, with the increase of every 10°C, the rate of metabolic activities doubles. This rule is referred to as the Vant Hoffs rule. Vant Hoffs’s rule can also be stated in reverse saying that the reaction rate is halved with the decrease of every 10°C. The effect of temperature on the rate of a reaction is expressed in terms of temperature coefficient or Q10 value. Q10 values are estimated by taking the ratio between the rate of a reaction at X°C and the rate of reaction at (X-10°C). In the ‘living systems’ the Q10 value is about 2.0. If the Q10 value is about 20, it means, for every 10°C increase, the rate of metabolism doubles.

Cyclomorphosis: The cyclic seasonal morphological variations among certain organisms are called cyclomorphosis. This phenomenon has been demonstrated in the Cladoceran (a subgroup of Crustacea) and Daphnia (water flea). In the winter season, the head of Daphnia is ’round’ in shape (typical or non helmet morph). With the onset of the spring season, a small ‘helmet’/’hood’ starts developing on it. The helmet attains the maximum size in summer. In ‘autumn’ the helmet starts receding. By the winter season, the head becomes round. Some scientists are of the opinion that Cyclomorphosis is a seasonal adaptation to changing densities of the water in lakes. In summer as the water is less dense Daphnia requires a larger body surface to keep floating easily. During winter the water is denser, so it does not require a larger surface area of the body to keep floating.

Temperature adaptations: Temperature adaptations in animals can be dealt with under three heads:
(a) Behavioural adaptations
(b) Morphological and Anatomical adaptations and
(c) Physiological adaptations.

(a) Behavioural adaptations: Some organisms show behavioural responses to cope with variations in their environment. Desert lizards manage to keep their body temperature fairly constant by behavioural means. They bask (staying in the warmth of sunlight) in the sun and absorb heat when their body temperature drops below the comfort zone, but move into the shade when the temperature starts increasing. Some species are capable of burrowing into the soil to escape from the excessive heat above the ground level.

(b) Morphological and anatomical adaptations: In the polar seas, aquatic mammals such as the seals have a thick layer of fat (blubber) that acts as an insulator and reduces the loss of body heat, underneath their skin. The animals which inhabit the colder regions have larger body sizes with greater mass. The body mass is useful to generate more heat. As per Bergmann’s rule mammals and other warm-blooded living in colder regions have less surface area to body volume ratio. Then their counterparts live in the tropical regions. The small surface area helps to conserve heat. For instance, the body size of American moose/Eurasian elk (Alces alces), increases with the latitudes in which they live. Moose in the northern part of Sweden show 15-20% more body moss than the same species (counterparts) living in southern Sweden.

Mammals from colder climates generally have shorter earlobes and limbs (extremities of the body) to minimize heat loss. Large earlobes and long limbs increase the surface area without changing the body volume. This is known as Allen’s rule. For instance, the polar fox, Vulpes lagopus (formerly called Alopex lagopus) has short extremities to minimize the heat loss from the body. In contrast, the desert fox has short extremities to minimize heat loss from the body. In contrast, the desert fox, Vulpes zerda, has large ear lobes and limbs to facilitate better heat loss from the body.

(c) Physiological adaptations: In most animals, all the physiological functions proceed ‘optimally’ in a narrow temperature range (in humans, it is 37°C). But there are microbes (archaebacteria) that flourish in hot springs and in some parts of deep seas, where temperatures far exceed 100°C. Many fish thrive in Antarctic waters where the temperature is always below zero. Having realized that the abiotic conditions of many habitats may vary over a time period, we now ask. How do the organisms living in such habitats manage stressful conditions?

One would expect that during the course of millions of years of their existence, many species would have evolved a relatively constant internal (within the body) environment. It permits all biochemical reactions and physiological functions to proceed with maximal efficiency and thus, enhance the overall fitness of the species. This constancy could be chiefly in terms of optimal temperature and osmotic concentration of body fluids. So the organism should try to maintain the constancy of its internal environment (homeostasis) despite varying external environmental conditions that tend to upset its homeostasis. This is achieved by the processes described below.

Thermal migration: The organism can move away temporarily from the stressful habitat to a more hospitable (comfortable) area and return when the stressful period is over. In human analogy comparison, this strategy is comparable to a person moving from Delhi to Shimla for the duration of summer. Many animals, particularly birds, during winter undertake long-distance migrations to more hospitable areas. Every winter, many places in India including the famous Keoladeo Ghana National Park (Formerly – Bharatpur bird sanctuary) in Rajastan and Pulicat Lake in Andhra Pradesh host thousands of migratory birds coming from Siberia and other extremely cold northern regions.

Diapause: Certain organisms show a delay in development, during periods of unfavourable environmental conditions and spend periods in a state of inactiveness called diapause. This dormant period in animals is a mechanism to survive extremes of temperature drought, etc. It is seen mostly in insects and embryos of some fish. Under unfavourable conditions, many zooplankton species in Lakes and ponds are known to enter diapause.

Question 2.
Write an essay on water as an ecological factor.
Answer:
Water is another important factor influencing the life of organisms. Life is unsustainable without water. Its availability is so limited in deserts that only certain special adaptations make it possible for them to live there. You might think that organisms living in oceans, lakes, and rivers should not face any water-related problems, but It is not true. For aquatic organisms the quality (chemical composition, pH, etc.) of water becomes important. The salt concentration is less than 5 percent in inland waters and 30-35 percent in seawater. Some organisms are tolerant to a wide range of salinities (euryhaline) but others are restricted to a narrow range (stenohaline) Many freshwater animals cannot live for long in seawater and vice versa because of the osmotic problems, they would face.

Adaptations in freshwater habitat: Animals living in freshwater have to tackle the problem of endosmosis. The osmotic pressure of freshwater is very low and that of the body fluids of freshwater organisms is much higher. So water tends to enter into bodies by endosmosis. To maintain the balance of water in the bodies, the freshwater organisms acquired several adaptations such as contractile vacuoles in the freshwater protozoans, large glomerular kidneys in fishes, etc… They send out large quantities of urine freshwater fishes have salt-absorbing ‘chloride cells’ in their gills. The major problem in freshwater ponds is – in summer most of the ponds dry up. To overcome this problem, most of the freshwater protists undergo encystment. The freshwater sponges produce asexual reproductive bodies, called gemmules to tide over the unfavorable conditions of the summer. The African lungfish, Protopterus, burrows into the mud and forms a gelatinous cocoon around it, to survive, in summer.

Adaptations in marine habitat: Seawater is high in salt content compared to that body fluids. So, marine animals continuously tend to lose water from their bodies by exosmosis and face the problem of dehydration. To overcome the problem of water loss marine fishes have glomerular kidneys with less number of nephrons. Such Kidneys minimize the loss of water through urine. To compensate for water loss marine fish drink more water, and along with this water, salts are added to the body fluids and disturb the internal equilibrium.

To maintain salt balance (salt homeostasis) in the body they have salt-secreting chloride cells in their gills. Marine birds like seagulls and penguins eliminate salts in the form of salty fluid that drips through their nostrils. In turtles, the ducts of chloride-secreting glands open near the eyes. Some cartilaginous fishes retain urea and trimethylamine oxide (TMO) in their blood to keep the body fluid isotonic to the seawater and avoid dehydration of the body due to exosmosis.

Water-related adaptations in brackish water animals: The animals of brackish water are adapted to withstand wide fluctuations in salinity. Such organisms are called euryhaline animals and those that cant with stand is known as stenohaline. The migratory fishes such as salmon and Hilsa are anadromous fishes i.e. they ‘migrate from the sea to freshwater, for breeding; Anguilla bengalensis is a catadromous fish i.e. it migrates from the river to sea, for breeding. In these fishes, their glomerular kidneys are adjusted to changing salinities. The chloride cells are adapted to excrete or absorb salts depending on the situation. On entering the river they drink more freshwater to maintain the concentration of body fluids equal to that of the surrounding water.

Water-related adaptations for terrestrial life: In the absence of an external source of water, the Kangaroo rat of the North American deserts is capable of meeting all its water requirements through oxidation of its internal fat (in which water is a by-product – of metabolic water). It also has the ability to concentrate its urine, so that minimal volume of water is lost in the process of removal of its excretory products.

Question 3.
Describe the lake as an ecosystem giving examples for the various zones and the biotic components in it.
Answer:
Deep water lakes contain three distinct zones namely

• Littoral zone
• Limnetic zone
• Profundal zone

Littoral Zone: It is the shallow part of the lake closer to the shore. Light penetrates up to the bottom. It is euphotic (having good light) and has rich vegetation and a higher rate of photosynthesis, hence rich in oxygen.

Limnetic Zone: It is the open water zone away from the shore. It extends up to the effective light penetration level, vertically. The imaginary line that separates the limnetic zone from the profundal zone is known as the zone of compensation/compensation point light compensation level. It is the zone of effective light penetration. Here the rate of photosynthesis is equal to the rate of respiration. The limnetic zone has no contact with the bottom of the lake.

Profundal Zone: It is the deep water area present below the limnetic zone and beyond the depth of effective light penetration. Light is absent. Photosynthetic organisms are absent and so the water is poor in oxygen content. It includes mostly the anaerobic organisms which feed on detritus. The organisms living in lentic habitats are classified into pedantic forms, which live at the bottom of the lake and those living in the open waters of lakes, away from the shore vegetation are known as limnetic forms.

Biota (animal and plant life of a particular region) of the littoral zone: Littoral zone is rich with pedantic flora (especially up to the depth of the effective light penetration). At the shore, proper emergent vegetation is abundant with firmly fixed roots at the bottom of the lake, and shoots and leaves are exposed above the level of water. These are amphibious plants. Certain emergent rooted plants of the littoral zone are the cattails (Typha), bulrushes (Scirpus) arrowheads (Sagittaria),. Slightly deeper are the rooted plants with floating leaves, such as the water lilies (Nymphaea), Nelumbo, Trapa, etc., still deeper are the submerged plants such as Hydrilla – Chara, Potamogeton, etc… The free-floating vegetation includes pistia, Wolffia, Lemna (duckweed), Azolla, Eichhornia, etc.

The phytoplankton of the littoral zone is composed of diatoms (Coscinodiscus, Nitzschia, etc) green algae (Volvox, spirogyra, etc), euglenoids (Euglena, phacus, etc), and dinoflagellates (Gymnodinium, Cystodinium, etc ….)

Animals, the consumers of the littoral zone, are abundant in this zone of the lake, these are categorized into zooplankton, neuston, nekton, periphyton, and benthos. The Zoo-plankton of the littoral zone consists of water fleas such as Daphnia, rotizers, and ostracods.

The animals living at the air-water interface constitute the neuston. They are of two types. The epineuston and hyponeuston. Water striders (Gerris), beetles, and water bugs (Dineutes) form the epineuston/ supraneuston and the hyponeuston/infraneuston includes the larvae of mosquitoes.

The animals such as fishes, amphibians, water-snakes, terrapins, insects like water scorpion (Ranatra), back swimmer (Notonecta), diving beetles (Dytiscus), capable of swimming constitute the nekton.

The animals that are attached to/creeping on the aquatic plants, such as the ‘water snails’, nymphs of insects, bryozoans, turbellarians, hydras, etc, constitute the periphyton. The animals that rest on or move on the bottom of the lake constitute the ‘benthos’, e.g.: red annelids, chironomid larvae, crayfishes, some isopods amphipods, clams, etc.

Biota of the limnetic zone: Limnetic zone is the largest zone of a lake. It is the region of rapid variations of the level of the water, temperature, oxygen availability, etc., from time to time. The limnetic zone has autotrophs (photosynthetic plants) in abundance. The chief autotrophs of this region are the phytoplankton such as the euglenoids, diatoms, cyanobacteria, dinoflagellates, and green algae. The consumers of the limnetic zone are the zooplanktonic organisms such as the copepods, Fisher frogs, water snakes, etc., which form the limnetic nekton.

Biota of the profundal zone: It includes the organisms such as decomposers (bacteria), chironomid larvae, Chaoborus (phantom larva), red annelids, clams, etc., that are capable of living in low oxygen levels. The decomposers of this zone decompose the dead plants and animals and release nutrients that are used by the biotic communities of both littoral and limnetic zones.

The lake ecosystem performs all the functions of any ecosystem and of the biosphere as a whole, i.e., conversion of inorganic substances into organic material, with the help of the radiant solar energy by the autotrophs, consumption of the autotrophs by the heterotrophs; decomposition and mineralization of the dead matter to release them back for reuse by the autotrophs (recycling of minerals).

Question 4.
Describe different types of food chains that exist in an ecosystem.
Answer:
The food energy passes from one trophic level to another trophic level mostly from the lower to higher trophic levels. When the path of food energy is ‘linear’ the components resemble the ‘links’ of a chain and it is called a ‘food chain’. Generally, a food chain ends with decomposers. The three major types of food chains in an ecosystem are the Grazing Food Chain, Parasitic Food Chain, and Detritus Food Chain.

(i) Grazing food chain: It is also known as the predatory food chain, it begins with the green plants (producers), and the second third, and fourth trophic levels are occupied by the herbivores, primary carnivores, and secondary carnivores respectively. In some food chains, these are yet another trophic level – the climax carnivores. The number of trophic levels in food chains varies from 3 to 5 generally. Some examples from the grazing food chain (GFC) are given below.

(ii) Parasitic food chain: Some authors included the Parasitic Food Chains as a part of the GFC. As in the case of GFC’s, it also begins with the producers, the plants (directly or indirectly). However, the food energy passes from large organisms to small organisms in the parasitic chains. For instance, a tree that occupies the 1st trophic level provides shelter and food for many birds. These birds host many ectoparasites and endo parasites. Thus, unlike in the predator food chain, the path of the flow of energy includes fewer, large-sized organisms in the lower trophic levels and numerous, small-sized organisms in the successive higher trophic levels.

(iii) Detritus Food Chain: The detritus food chain (DFC) begins with dead organic matter (such as leaf litter, and bodies of dead organisms). It is made up of decomposers which are heterotrophic organisms, mainly fungi’ and ‘bacteria’. They meet their energy and nutrient requirements by degrading dead organic matter or detritus. These are also known as saprotrophs (sappro: to decompose).

Decomposers: Secrete digestive enzymes that break down dead and waste materials (such as feces) into simple absorbable substances. Some examples of detritus food chains are:

• Detritus (formed from leaf litter) – Earthworms – Frogs – Snakes
• Dead animals – Flies and maggots – Frogs – Snakes.

In an aquatic ecosystem, GFC is the major ‘conduit for the energy flow. As against this in a terrestrial ecosystem, a much larger fraction of energy flows through the detritus food chain than through the GFC. The Detritus food chain may be connected with the grazing food chain at some levels. Some of the organisms of DFC may form the prey of the GFC animals. For example, in the detritus food chain given above, the earthworms of the DFC may become the food of the birds of the GFC. It is to be understood that food chains are not ‘isolated’ always.

Question 5.
Give an account of the flow of energy in an ecosystem.
Answer:
Except for the deep sea hydro-thermal ecosystem, the sun is the only source of energy for all ecosystems on Earth. Of the incident solar radiation, less than 50 percent of it is photosynthetically active radiation (PAR). We know that plants and photosynthetic bacteria (autotrophs), fix the sun’s radiant energy to synthesize food from simple inorganic materials. Plants capture only 2-10 percent of the PAR and this small amount of energy sustains the entire living world. So, it is very important to know how the solar energy captured by plants flows through different organisms of an ecosystem. All heterotrophs are dependent on the producers for their food, either directly or indirectly. The law of conservation of energy is the first law of thermodynamics. It states that energy may transform from one form into another form, but it is neither created nor destroyed. The energy that reaches the earth is balanced by the energy that leaves the surface of the earth as invisible heat radiation.

The energy transfers in an ecosystem are essential for sustaining life. Without energy transfers, there could be no life and ecosystem. Living beings are the natural proliferations that depend on the continuous inflow of concentrated energy. Further, ecosystems are not exempted from the Second Law of thermodynamics. It states that no process involving energy transformation will spontaneously occur unless there is the degradation of energy. As per the second law of thermodynamics – the energy dispersed is in the form of unavailable heat energy and constitutes the entropy (energy lost or not available for work in a system).

The organisms need a constant supply of energy to synthesize the molecules they require. The transfer of energy through a food chain is known as energy flow. A constant input of mostly solar energy is the basic requirement for any ecosystem to function. The important point to note is that the amount of energy available decreases at successive trophic levels. When an organism dies, it is converted to detritus or dead biomass that serves as a source of energy for the decomposers. Organisms at each trophic level depend on those at the lower trophic level, for their energy demands.

Each trophic level has a certain mass of living material at a particular time and it is called the standing crop. The standing crop is measured as the mass of living organisms (biomass) or the number of organisms per unit area. The biomass of a species is expressed in terms of fresh or dry weight (dry weight is more accurate because water contains no usable energy).

The 10 percent Law: The 10 percent law for the transfer of energy from one trophic level to the next was introduced by Lindeman (the Founder of modern Ecosystem Ecology). According to this law, during the transfer of energy from one trophic level to the next, only about 10 percent of the energy is stored/converted as body mass/biomass. The remaining is lost during the transfer or broken down in catabolic activities (Respiration). Lindeman’s rule of trophic efficiency/Gross ecological efficiency is one of the earliest and most widely used measures of ecological efficiency. For example: If the NPP (Net Primary Production) in a plant is 100 kJ, the organic substance converted into the body mass of the herbivore which feeds on it is 10 kJ only. Similarly, the body mass of the carnivore-I is 1 kJ only.

Question 6.
List out the major air pollutants and describe their effects on human beings.
Answer:
Air pollutants cause injury to all living organisms. They reduce the growth and yield of crops. They are harmful to the respiratory system of humans and animals. An increase in the concentration of pollutants or duration of exposure increases the harmful effects on the organisms.
The major air pollutants:
1. Carbon monoxide (CO): It is produced mainly due to incomplete combustion of fossil fuels. Automobiles are a major cause of CO pollution in larger cities and towns. Automobile exhausts, fuels from factories, emissions from power plants, forest fires and even burning of firewood contribute to CO pollution. Haemoglobin has a greater affinity for CO and SO, and CO competitively interferes with oxygen transport. CO symptoms such aS headache and blurred vision at lower concentrations. In higher concentrations, it leads to coma and death.

2. Carbon Dioxide (CO₂): Carbon dioxide is the main pollutant that is leading to global warming. Plants utilize CO₂ for photosynthesis and all living organisms emit carbon dioxide in the process of respiration. With rapid urbanization, automobiles, aeroplanes, power plants, and other human activities that involve the burning of fossil fuels such as gasoline, carbon dioxide is turning out to be an important pollutant of concern.

3. Sulphur Dioxide (SO₂): It is mainly produced by burning fossil fuels. Melting of sulphur ores is another important source of SO2 pollution. The metal smelting and other industrial processes also contribute to SO₂ pollution. Sulfur dioxide and nitrogen oxides are the major causes of acid rains, which cause acidification of soils, lakes, and streams and also accelerated corrosion of buildings and monuments. High concentrations of sulphur dioxide (SO₂) can result in breathing problems in asthmatic children and adults. Other effects associated with long-term exposure to sulphur dioxide, include respiratory illness, alterations in the lungs defenses, and aggravation of existing cardiovascular problems.

To control SO₂ pollution, the emissions are filtered through scrubbers. Scrubbers are devices that are used to clean the impurities in exhaust gases. Gaseous pollutants such as SO₂ are removed by scrubbers.

4. Nitrogen Oxides: Nitrogen oxides are considered to be major primary pollutants. The source is mainly automobile exhaust. The air polluted by nitrogen oxide is not only harmful to humans and animals but also dangerous for the life of plants. Nitrogen oxide pollution also results in acid rain and the formation of photochemical smog. The effect of nitrogen oxides on plants includes the occurrence of necrotic spots on the surface of leaves. Photosynthesis is affected in crop plants and the yield is reduced. Nitrogen oxides combine with volatile organic compounds by the action of sunlight to form secondary pollutants called Peroxyacetyl nitrate (PAN) which are found especially in photochemical smog. They are powerful irritants to the eyes and respiratory tract.

5. Particulate matter/Aerosols: Tiny particles of solid matter suspended in a gas or liquid constitute the particulate matter. Aerosols refer to particles and /or liquid droplets and the gas together (a system of colloidal particles dispersed in a gas) Combustion of “fossil fuels” (petrol, diesel, etc) fly ash produced in thermal plants, forest fires, cement factories, asbestos mining, and manufacturing units, spinning and ginning mills, etc., are the main sources of particulate matter pollution. According to the Central Pollution Control Board (CPCB) particles of 2.5 micrometers or less in diameter are highly harmful to man and other air-breathing organisms.

An electrostatic precipitator is a widely used filter’ for removing particulate matter from the exhaust of thermal power plants. It can remove 99% of particulate matter. It has high voltage electrodes which produce a ‘corona’ that releases electrons. These are collected by collecting plates that attract charged particles. The air flowing between the plates is kept at a low velocity so as to allow the dust particles to fall. Thus clean air is released into the atmosphere.

Question 7.
What are the causes of water pollution and suggested measures for control of water pollution?
Answer:
Domestic Sewage: Sewage is the major source of water pollution in large cities and towns. It mainly consists of human and animal excreta and other waste materials. It is usually released into freshwater bodies or the sea directly. As per the regulations the sewage has to be passed through treatment plants before it is released into the water sources. Only 0.1 percent of impurities from domestic sewage are making these water sources unfit for human consumption. In the treatment of sewage, solids are easy to remove. Removal of dissolved salts such as nitrates, phosphates, and other nutrients and toxic metal ions and organic compounds is much more difficult. Domestic sewage primarily contains biodegradable organic matter, which will be readily decomposed by the action of bacteria and other microorganisms.

Biological Oxygen Demand (BOD): BOD is a measure of the content of biologically degradable substances in sewage. The organic degradable substances are broken down by microorganisms using oxygen. The demand for oxygen is measured in terms of the oxygen consumed by microorganisms over a period of 5 days (BOD 5) or seven days (BOD 7). BOD forms an index for measuring pollution load in the sewage. Microorganisms involved in the biodegradation of organic matter in water bodies consume a lot of oxygen and as a result, there is a sharp decline in dissolved oxygen causing the death of fish and other aquatic animals.

Algal blooms: The presence of large amounts of nutrients in waters also causes excessive growth of plankton algae and the phenomenon is commonly called “algal blooms1′. Algal blooms impart distinct colour to the bodies and deteriorate the quality of water. It also causes the mortality of fish. Some algae which are involved in algal blooms are toxic to human beings and animals.

Excessive growth of aquatic plants such as the common water hyacinth (Eichhornia crassipes), the world’s most problematic aquatic weed which is also called “Terror of Bengal” causes blocks in our waterways. They grow faster than our ability to remove them. They grow abundantly in eutrophic water bodies (water bodies rich in nutrients) and lead to an imbalance in the ecosystem dynamics of the water body.

Sewage arising from homes and hospitals may contain undesirable pathogenic microorganisms. If it is released untreated into water courses, there is a likelihood of an outbreak of serious diseases, such as dysentery, typhoid, jaundice, cholera, etc.

2. Industrial Effluents: Untreated industrial effluents released into water bodies pollute most of the rivers, freshwater streams, etc. Effluents contain a wide variety of both inorganic and organic pollutants such as oils, greases, plastics, metallic wastes, suspended solids, and toxins. Most of them are non-degradable. Arsenic, Cadmium, Copper, Chromium, Mercury, Zinc, and Nickel are the common heavy metals discharged from industries.

Effects: Organic substances present in the water deplete the dissolved oxygen content in water by increasing the BOD (Biological Oxygen Demand) and COD (Chemical Oxygen Demand). Most of the inorganic substances render the water unfit for drinking. Outbreaks of dysentery, typhoid, jaundice, cholera, etc., are caused by sewage pollution.

Biomagnification: Increase in the concentration of the pollutant or toxicant at successive trophic levels in an aquatic food chain is called Biological Magnification or Bio-magnification. This happens in the instances where a toxic substance accumulated by an organism is not metabolized or excreted and thus passes on to the next higher trophic level. This phenomenon is well known regarding DDT and mercury pollution.

As shown in the above example, the concentration of DDT is increased at successive trophic levels starting at a very low concentration of 0.003 ppb (ppb = parts per billion) in water, which ultimately reached an alarmingly high concentration of 25 ppm (ppm = parts per million) in fish-eating birds, through biomagnification. High concentrations of DDT disturb calcium metabolism in birds, which causes thinning of eggshells and their premature breaking, eventually causing a decline in bird populations.

Eutrophication: Natural ageing of a lake by nutrient enrichment of its water is known as eutrophication. In a young lake, the water is cold and clear, supporting little life. Gradually nutrients such as nitrates and phosphates are carried into the lake via streams, in course of time. This encourages the growth of aquatic algae and other plants. Consequently, animal life proliferates and organic debris piles up, the lake grows shallower and warmer. As a result, the aquatic organisms thriving in the cold environment are gradually replaced by warm-water organisms. Marsh plants appear by taking root in the shallow regions of the lake. Eventually, the lake gives way to large masses of floating plants (bog) and is finally covered in land.

Andhra Pradesh BIEAP AP Inter 1st Year Zoology Study Material Lesson 7 Type Study of Periplaneta Americana (Cockroach) Textbook Questions and Answers.

AP Inter 1st Year Zoology Study Material Lesson 7 Type Study of Periplaneta Americana (Cockroach)

Very Short Answer Type Questions

Question 1.
Why do you call cockroaches a pest?
Answer:
The cockroach is a common household pest that contaminates our food with its excreta and can transmit a number of diseases.

Question 2.
Name the terga of thoracic segments of cockroaches.
Answer:
Tergum of prothorox is Pronotum.
The tergum of mesothorax is Mesonotum.
The tergum of metathorax is Metanotum.

Question 3.
What are the structures with which cockroach walks on smooth surfaces and on rough surfaces respectively?
Answer:
The claws and the arotium help in locomotion on rough surfaces whereas planulae are useful on smooth surfaces.

Question 4.
Why is the head in cockroach called hypognathous?
Answer:
It lies hinging almost a right angles to the body with the posterior wider part upwards and the mouth parts directed downwards.

Question 5.
How is a tripod formed With reference to locomotion in cockroach?
Answer:
Tripod is formed by foreleg and hind leg of one side middle leg of other side. The fore leg and hind leg of the tripod kept on the ground, pull and push the body, while the middle leg acts as a pivot.

Question 6.
Name the muscles that help in elevating and depressing the wings of a cockroach.
Answer:
Wings are elevated by the contraction of dorsoventral muscles. Contraction of the dorsa longitudinal muscles depresses the muscles.

Question 7.
Name the different blood sinuses in cockroach.
Answer:
The three sinuses of haemocoel are known as
Pericardial haemocoel/Dorsal sinus
Perivisceral haemocoel/middle sinus
Perineural haemocoel/ventral sinus.

Question 8.
How are the fat bodies similar to the liver of the vertebrates?
Answer:
Fat bodies have many cells that are similar to the liver of the vertebrates in certain functions, namely
Trophocytes (store food)
Mycetocytes (contain symbiotic bacteria)
Oenocytes (secrete lipids)
Urate cells (store uric acid)

Question 9.
Which part of the gut secretes the peritrophic membrane in cockroach?
Answer:
Peritrophic membrane is secreted by the funnel like stomodel valve of the gizzard of midgut.

Question 10.
In which part of the gut of cockroach, water is reabsorbed?
Answer:
Rectum reabsorbes the water in cockroach.

Question 11.
Write the names of mouthparts in cockroach that help in biting and tasting the food.
Answer:
Mandibles helps in biting and labrum helps in tasting the food.

Question 12.
What are alary muscles?
Answer:
A services of paired triangular muscles that are present in the dorsal and ventral diaphragm.

Question 13.
What is haemocoel?
Answer:
In cockroach blood (or) haemolymph flows freely with in the body cavity (or) haemocoel.

Question 14.
The three sinuses in a cockroach are not equal in size. Why?
Answer:
The middle sinus is very large as it contains most of the viscera. The dorsal and ventral sinuses are small as they have only heart and nerve cord.

Question 15.
Why is the blood of Periplaneta called haemolymph?
Answer:
The blood of periplaneta is colourless and it consists of fluid plasma and blood cells. Hence blood of periplaneta is called haemolymph.

Question 16.
What is the function of haemocytes found in the blood of Periplaneta?
Answer:
Haemocytes are phagocytic in nature. These are large in size and can ingest foreign particles.

Question 17.
Why does not the blood of Periplaneta help in respiration?
Answer:
Due to the absence of respiratory pigment the blood of cockroach can’t carry oxygen to different tissues.

Question 18.
Write important functions of blood in Periplaneta.
Answer:
1. It absorbs digest food from alimentary canal and distributes it to the rest of the body.
2. It transports secretions of the ductless glands to the target organs.

Question 19.
How many spiracles are present in cockroach? Mention their locations.
Answer:
Ten pairs of spiracles are present in cockroach.
Location: First two pairs of spiracles are present in the thoracic segments, remaining eight pairs present in first eight abdominal segments. Spiracles are located in the pleura of their respective segment.

Question 20.
What are trichomes? Write their functions.
Answer:
Trichomes are small hair-like structures of spiracles.
Function: Filtering the dust particles.

Question 21.
Why is the respiratory system of cockroaches called polytheistic and holocaustic systems?
Answer:
The spiracles of cockroaches are more in number (10 pairs) and all are functional so the respiratory system of cockroaches is called polytheistic and holocaustic systems.

Question 22.
What is intima?
Answer:
A cuticle layer that forms the inner layer of trachea is called intima.

Question 23.
During inspiration which spiracles are kept open and which are kept closed?
Answer:
Thoracic spiracles are kept open and the abdominal spiracles are kept closed.

Question 24.
Which factors regulate the opening of the spiracles?
Answer:
Opening and closing of spiracles is influenced by CO2 tension in haemolymph and oxygen tension in the trachea.

Question 25.
Inspiration in cockroach is a passive process and expiration is an active process. Justify?
Answer:
As air is drawn in due to the relaxation of the muscle inspiration is a “passive process”. Expiration involves the contraction of muscles, so it is described as active process.

Question 26.
The nitrogenous wastes in Periplaneta are removed from the body through alimentary canal. Why?
Answer:
Malphigian tubules collect nitrogenous acts from the body parts and releases into alimentary canal. So these nitrogenous wastes get mixed with facel matter and sent out through anus.

Question 27.
How does the cuticle of a cockroach help in excretion?
Answer:
Some nitrogenous waste materials are deposited on the cuticle and eliminated during moulting.

Question 28.
How do fat bodies help in excretion?
Answer:
Urate cells present in these bodies are associated with excretion in a way. Those cells absorb and store uric acid.

Question 29.
What is ‘storage excretion’?
Answer:
Urate cells present in the fat bodies absorb and store uric acid throughout life. This is called “storage excretion”.

Question 30.
Which structure of the cockroach acts as a sensory and endocrine centre?
Answer:
The brain of the cockroach acts as the sensory and endocrine centre.

Question 31.
Distinguish between scolopidia and sensillae.
Answer:

Question 32.
How is the ommatidium of cockroaches different from that of diurnal insects?
Answer:
Retinulae are present deep below the vitrallae and crystalline cone. The retinal sheath is absent.

Question 33.
Which of the abdominal ganglia is the largest and why?
Answer:
6th abdominal ganglia are the largest of all the abdominal ganglia because it is formed by the fusion of the ganglia of the 7th, 8th, 9th & 10th abdominal segments.

Question 34.
Name the structural and functional unit of the compound eye of the cockroach. How many such units are present in a single compound eye?
Answer:
Each compound eye is composed of about 2000 functional units called ommatidia.

Question 35.
Why is the brain called the principal sensory centre in cockroaches?
Answer:
The brain receives sensory impulses from various mouth parts & compound eye. Hence the brain is the principally a sensory centre.

Question 36.
Distinguish between apposition image and superposition image.
Answer:

Question 37.
List out the characters that help in understanding the difference between male and Female cockroaches.
Answer:

Question 38.
What is the function of the mushroom gland in cockroaches?
Answer:
A characteristic mushroom-shaped gland is present in the 6th and 7th abdominal segments which functions as an accessory reproductive gland.

Question 39.
Compare the utriculi majors and utriculi breviores of the mushroom gland functionally.
Answer:

• Utriculi majores forms the inner layer of the spermatophore.
• Utriculi breviores nourish the sperms.

Question 40.
What are Phallomeres?
Answer:
Surrounding the male genital opening there are chitinous and asymmetrical structures called phallic organs/phellomeres/gonapophyses which help in copulation.

Question 41.
What is gona Pophyses?
Answer:
Surrounding the male genital opening there are chitinous and asymmetrical structures called phallic organs/phellomeres/gonapophyses which help in copulation.

Question 42.
How is the colleterial gland helpful in the reproduction of Periplaneta?
Answer:
A pair of branched colleterial glands is present behind the ovaries. These glands open into the genital pouch separately. Secretions of the two collateral glands form a hard egg case called Ootheca.

Question 43.
What is paurometabolous development?
Answer:
Gradual development (metamorphosis) through nymph stages is called “parametabolous development”.
Ex: Periplaneta

Short Answer Type Questions

Question 1.
Draw a neat labelled diagram of the mouthparts of cockroaches.
Answer:

Question 2.
Describe the physiology of digestion in cockroaches.
Answer:
Food collection: The cockroach is an omnivorous insect. It feeds on all types of organic matter.

Digestion: After swallowing, the food passes through the pharynx and oesophagus and reaches the crop. In the crop, food is mixed with digestive juices that are regurgitated into it through the grooves of the gizzard. Hence, most of the food is digested in the crop. The partly digested food is filtered by the bristles of the gizzard and later it passes through the stomodeal valve into the ventricular.

The enzyme amylase of the salivary juice converts starches into disaccharides. Invertase or sucrase digests sucrose into glucose and fructose. Maltose converts maltose into glucose. The enzyme lipase digests lipids into fatty acids and glycerol. Proteases digest proteins into amino acids. The cellulose of the food is digested by the enzyme cellulose secreted by the microorganisms present in the hindgut of cockroaches. Cellulose is converted into glucose.

In the ventriculus, the digested food is absorbed. The undigested food is passed into the ileum, and colon and then reaches the rectum, where water is reabsorbed by rectal papillae. Then the remaining material is finally defecated as dry pellets, through the anus.

Question 3.
Draw a neat labelled diagram of the salivary apparatus of cockroaches.
Answer:

Question 4.
Describe the structure and function of the heart in Periplaneta.
Answer:
Heart: The heart lies in the pericardial hemocoel or dorsal sinus. It is a long muscular, contractile tube found along the mid-dorsal line, beneath the terga of the thorax and abdomen. It consists of 13 chambers. Every chamber opens into the other present in front of it. Three of the thirteen chambers are situated in the thorax and ten in the abdomen. Its posterior end is closed while the anterior end is continued forward as the anterior aorta. On the posterior side of each chamber, except the last, there is a pair of small apertures called ‘Ostia’ one on each side. Ostia have valves that allow the blood to pass only into the heart from the dorsal sinus.

Question 5.
Describe the process of blood circulation in Periplaneta.
Answer:
The blood flows forward in the heart by the contractions of its chambers. At the anterior end of the heart, the blood flows into the aorta and from there it enters the sinus of the head. From the head sinus, the blood flows into the perivisceral and sternal sinuses. On contraction of the alary muscles, the pericardial septum is pulled down. This increases the volume of the pericardial sinus. Hence blood flows from the perivisceral sinus into the pericardial sinus through the apertures of the pericardial septum. On relaxation of the alary muscles, the pericardial septum moves upwards to its original position. This forces the blood, to enter the chambers of the heart through the Ostia from the pericardial sinus.

Question 6.
How do contraction and relaxation of alary muscles help in circulation?
Answer:
The blood flows forward in the heart by the contractions of its chambers. At the anterior end of the heart, the blood flows into the aorta and from there it enters the sinus of the head. From the head sinus, the blood flows into the perivisceral and sternal sinuses. On contraction of the alary muscles, the pericardial septum is pulled down. This increases the volume of the pericardial sinus. Hence blood flows from the pericardial septum. On relaxation of the alary muscles, the pericardial septum moves upwards to its original position. This forces the blood, to enter the chamber of the heart through the Ostia from the pericardial sinus.

Question 7.
What are the different excretory organs in Periplaneta? Describe the process of excretion in detail.
Answer:
The structures associated with excretory function are Malpighian tubules, Fat bodies, uricase glands, Nephrocytes, and Cuticles.

Malpighian tubule: The malpighian tubules are long, unbranched yellowish tubules, attached at the extreme anterior end of the hindgut, lying freely in the hemolymph, but do not open into it being bliand at the free ends. They are 100-150 in number arranged in 6-8 bundles, each bundle having 15-25 tubules. Each tubule is lined by a single layer of glandular epithelium with a brush border on the inner surface. The ‘distal portion’ of the tubule is secretory and the ‘proximal part’ is absorptive in nature.

The glandular cells of the malpighian tubules absorb water salts, CO2, and nitrogenous wastes from the hemolymph and secrete them into the lumen of the tubules. The cell of the proximal part of the tubules reabsorbs water and certain inorganic salts. By the contraction of the tubules, urine is pushed into the ileum. More water is reabsorbed from it when it moves into the rectum and almost solid uric acid is excreted along with faecal matter.

The removal of nitrogenous waste material through the alimentary canal helps in the complete reabsorption of water from the wastes and the formation of dry uric acid. It is an adaptation for the conservation of water as it is very important in terrestrial organisms.

Fat bodies: Fat body is a lobed white structure. Urate cells present in these bodies are associated with excretion in a way. These cells absorb and store uric acid throughout life. This is called storage excretion as they remain stored in the cells of the corpora adipose.

Uricose glands: Uric acid is stored in uriosa gland or utriculi majority of the mushroom gland in male cockroaches. It is discharged during copulation.

Cuticle: Some nitrogenous waste materials are deposited on the cuticle and eliminated during moulting.

Question 8.
How does Periplaneta conserve water? Explain it with the help of excretion in it.
Answer:
Periplaneta can conserve water by following methods. The removal of Nitrogenous waste material through the alimentary canal helps in the complete reabsorption of water from the wastes and the formation of dry uric acid. It is an adaption for the conservation of water as it is very important in terrestrial organisms.

Cuticle: Some nitrogenous waste materials are deposited on the cuticle and eliminated during moulting.

Question 9.
Draw a neat and labelled diagram of Ommatidium.
Answer:

Question 10.
How can you identify the male and female cockroaches? Explain it describing the chief structures of the external and internal genitalia.
Answer:
Periplaneta is dioecious or unisexual and both the sexes have well-developed reproductive organs. Sexual dimorphism is evident both externally and internally. The female is different from the male in respect of short and broad abdomen, presence of blood pouches, and absence of anal styles.

The eighth tergum in the male and both the eighth and ninth terga in the female are not visible. In the male ninth sterna are visible, whereas in the female only the seventh sterna are visible. The seventh, eighth, and ninth sterna together form a broad pouch.

The posterior end of the abdomen is a pair of anal cerci, a pair of anal styles and gonophophyses in the males, and cerci are jointed and arise from the lateral side of the tenth tergum and are found in both sexes. The anal styles are without joints and arise from the ninth sternum. But seen only in the males. The gonopophysis are small chitinous processes arising from the ninth sternum in males and the eighth, and ninth sterna in females. They are the external genital organs.

Question 11.
Describe the male reproductive system of cockroaches.
Answer:
The male reproductive system consists of a pair of testes. These are elongated and lobed structures lying on each lateral side in the fourth to sixth abdominal segments. They are embedded in the fat bodies. From the posterior end of each testis, there starts a thin duct, the vas deferens.

The two vasa deferentia run backward and inwards to open into a wide median duct, the ductus ejaculatory in the seventh segment. A characteristic mushroom-shaped gland is present in the 6th and 7th abdominal segments which functions as an accessory reproductive gland.

The gland consists of two types of tubules:

• Long slender tubules, the utriculi majors, or peripheral tubules.
• Short tubules, the utriculi breviores, and secretion of utriculi majors form the inner layer of the spermatophore while the utricular breviores nourish the sperms. These tubules open into the anterior part of the ejaculatory duct.

Question 12.
Describe the female reproductive system of cockroaches.
Answer:

The female reproductive system of Periplaneta consists of a pair of ovaries a pair of oviducts vagina, spermathecal papilla, colleterial glands, and ovaries.

A pair of large ovaries lie laterally in 2 to 6 abdominal segments. They are light yellow in colour surrounded by fat bodies. Each ovary consists of eight tubules called ovarian tubules or ovarioles. Each ovariole consists of a tapering anterior filament called germarium and a posterior wider vitellarium. The germarium contains various stages of developing ova and the vitellarium contains mature ova with the yolk. The tapering ends of the ovarioles of each ovary unite to form a single thread that attaches to the dorsal body wall.

The ovarioles, at their posterior end, unite to form a short wide oviduct. The oviducts unite to form a very short median vagina. The vertical opening of the vegina is called the female genital pore. It opens into a large genital pouch on the eighth sternum. A spermatheca or receptaculum seminis, consisting of a left-sac like and a right filamentous caecum, is present in the 6th segment which opens by a median aperture on a small spermathecal papilla in the dorsal wall of the genital pouch on the ninth sternum. In a fertile female, the spermatheca contains spermatophores, obtained during copulation.

A pair of branched colleterial glands is present behind the ovaries. These glands open into the genital pouch separately, just above the spermathecal aperture. Secretion of the two collateral glands forms a hard egg case called ootheca around the eggs.

Long Answer Type Questions

Question 1.
Describe the digestive system of cockroaches with the help of a neat labelled diagram.
Answer:
The digestive system of cockroaches consists of an alimentary canal and the associated glands. The preoral cavity surrounded by the mouth parts is present in front of the mouth. The hypopharynx divides into two chambers called cibagium (anterior) and salivarium (posterior).

Alimentary canal: The alimentary canal of cockroaches is a long tube and is coiled in some places. It extends between the mouth and the anus. It is divided into three regions namely the foregut of stomodaeum, midgut or mesenteron, and hindgut is internally lined by ectoderm. The mesenteron is lined by the endodermal cells.

Forgut or stomodaeum: The foregut includes the pharynx oesophagus, crop, and gizzard. It is internally lined by a chitinous cuticle. The mouth opens into the pharynx, which in turn leads into a narrow tubular oesophagus. The oesophagus opens behind into a thin-walled distensible sac called a crop. The crop serves as a reservoir for storing food. Its outer surface is covered by a network of tracheae.

Behind the crop, there is a thick-walled muscular proven- triculus or gizzard. The chitinous inner living of the gizzard has six powerful teeth, which form an efficient grinding apparatus. Behind each tooth is a hairy pad, which bears backwardly directed bristles. Among these plates, food is thoroughly ground into fine particles. These food particles are filtered by the bristles. The gizzard thus acts both as a grinding mill and also as a sieve. There is a membranous projection of the gizzard into the mesenteron in the form of a funnel called a stomodeal valve. This valve prevents the entry (regurgitation) of food from the mesenteron back into the gizzard.

Midgut (mesenteron or ventriculus): The midgut is a short and narrow tube behind the gizzard. It is also called mesenteron or ventriculus. Between the ventriculus and the gizzard, arising from the ventriculus there are six to the eighth finger-like diverticula called nepatic caecae. They are helpful in the digestion and absorption of digested food materials. Ventriculus is functionally divided into an anterior secretory part and a posterior absorptive part.

The secretory part of the ventriculus has many gland cells and it secretes several enzymes. The ‘bolus’ of food in the mesenteron is enveloped by a chitinous and porous membrane called a peritrophic membrane, which is secreted by the funnel-like stomodeal valve of the gizzard. Digested food is absorbed into the food through the peritrophic membrane in the posterior absorptive region of the ventriculus. The peritrophic membrane protects the wall of the ventriculus from hard food particles in the food. The opening of the ventriculus into the hindgut is controlled by a sphincture muscle. It prevents entry of undigested food from the hindgut into the midgut.

Hindgut or proctodaeum: The hindgut is a long coiled tube, consisting of three regions namely the ileum, colon, and rectum. It is internally lined by the chitinous cuticle. The ileum that lies behind the mesenteron is a short tube. Six bundles of fine yellow, blind tubules called Malpighian tubules open into the ileum near the junction of mesenteron and ileum. Malpighian tubules are excretory in function. The ileum collects uric acid from the malpighian tubules and undigested food from the mesenteron. The ileum opens behind into a long coiled tube called the colon. The colon leads into a short and wide rectum which opens out through the anus. The rectum bears on its inner side six longitudinal chitinous folds called rectal papillae. They are concerned with the reabsorption of water from undigested food.

Digestive gland: The digestive glands associated with the alimentary canal of cockroaches are salivary glands, hepatic caecae, and glandular cells of the mesenteron.

Salivary glands: There is a pair of salivary glands attached to the ventrolateral sides of the crop, one on each side. Each salivary gland has two lobes. Each lobe of the salivary gland has many lobules called acini. Each acinus is a group of secretory cells called zymogen cells with a small ductule. The ductules of both the lobes of a salivary gland unite to form a common salivary duct on each side.

The two common salivary ducts are joined to form the median salivary duct. Between the two lobes of a salivary gland on each side is a sac called the salivary receptacular duct or common reservoir duct. The midious salivary duct opens into the common receptacular duct. Later these two form an efferent salivary duct. The efferent salivary duct opens at the base of the hypopharynx. Acinar cells secrete saliva, which contains a starch digesting enzymes such as amylase.

Hepatic caecae: The hepatic caecae are also termed midguts caecae. They contain secretory and absorptive cells.

Glandular cells of the mesenteron: The glandular cells of the mesenteron secrete enzymes such as maltase, invertase, proteases, and lipase.

Question 2.
Describe the blood circulatory system of Periplaneta in detail and draw a neat and labelled diagram of it.
Answer:
The circulatory system helps in the transportation of digested food, hormones, etc., from one part to another in the body. Periplaneta has an open type of circulatory system as the blood or hemolymph, flows freely within the body cavity or hemocoel, Blood vessels are poorly developed and open into spaces) Visceral organs located in the hemocoel are bathed in the blood. The three main parts associated with the blood circulatory system of Periplaneta are the hemocoel, heart, and blood.

Haemocoel: The haemocoel of cockroaches is divided into three sinuses by two muscular, horizontal membranes called dorsal diaphragm or pericardial septum and ventral diaphragm. Both diaphragms have pores. There is a series of paired triangular muscles called alary muscles. Every segment has one pair of these muscles situated on the lateral sides of the body. These are attached to the pericardial septum by their broad bases and to the terga by their broad bases and to the terga by their pointed ends or apices. The three sinuses of the haemocoel are known as pericardial haemocoel or the dorsal sinus, the perivisceral haemocoel or the middle sinus, and sternal haemocoel or ventral sinus or perineural sinus. The middle sinus is very large as it contains most of the viscera. The dorsal and ventral sinuses are small as they have only the heart and nerve cords, respectively.

Heart: The heart lies in the pericardial haemocoel or dorsal sinus. It is a long muscular, contractile tube found in a long mid-dorsal line, beneath the terga of the thorax and abdomen.

It consists of 13 chambers. Every chamber opens into the other present in front of it. Three of the thirteen chambers are situated in the thorax and ten in the abdomen. Its posterior end is closed while the anterior end is continued forward as the anterior aorta. At the posterior side of each chamber, except the last, there is a pair of small apertures called ‘Ostia’ one on each side. Ostia have valves that allow the blood to pass only into the heart from the dorsal sinus.

Blood: The blood of Periplaneta is colourless and is called haemolymph. It consists of a fluid called plasma and free blood corpuscles or haemocytes, which are phagocytic. The phagocytic, the phagocytes are large in size and can ‘ingest’ foreign particles such as bacteria. There is no respiratory pigment in the blood and so it plays no major role in respiration.

Question 3.
Describe the respiratory system of cockroaches with the help of neat and labelled diagrams.
Answer:
Due to the absence of respiratory pigment, the blood of cockroaches is colourless and it cannot carry oxygen to different tissues. Therefore a tracheal system is developed to carry the air directly to the tissues. The respiratory system of cockroaches consists of stigmata, tracheae, and tracheoles.

Stigmata or spiracles: The tracheal system communicates with the exterior by ten pairs of openings called stigmata or spiracles. The first two pairs of spiracles are present in the thoracic segments, one pair in the mesothorax and one pair in the metathorax. The remaining eight pairs of abdominal segments.

Spiracles are located in the pleura of their respective segments. The respiratory system in insects is classified on the basis of the number and nature of spiracles. The spiracles of cockroaches are polypneustic (as they are more than 3 pairs) and holopneustic (as all of them are functional). All spiracles are valvular and each of them is surrounded by a chitinous ring called peritreme. All spiracles bear small hair-like structures called trichomes to filter the dust particles.

Each spiracle opens into a small chamber called the atrium.

Tracheae: From the atrium of each thoracic spiracle several horizontal tracheae run inside. They join with each other in the thorax to form many tracheal trunks like dorsal cephalic, and ventral cephalic trunks and their branches. These branches enter all organs of the head. The thoracic region also contains lateral longitudinal trunks. The abdominal spiracles lead into the atria. From the atrium of each abdominal spiracle, three tracheal tubes arise. All these tracheal tubes on one side open into three separate longitudinal tracheal trunks. They are lateral dorsal and ventral longitudinal trunks. Lateral longitudinal trunks are the longest tracheal trunks. The three pairs of longitudinal tracheal trunks on both sides are interconnected by many commissural tracheae. From all the tracheal trunks several branches are given out, which enter different organs. All tracheal branches entering an organ end in a special cell called tracheoles cell.

The wall of the tracheae is made of three layers. They are an outer basement membrane, a middle one cell thick epithelium, and an inner layer of cuticle called the intima. The intima is produced into spiral thickening called taenidia. The taenidia keep the tracheae always open and prevent it from collapsing.

Tracheoles: The terminal cell of the trachea is called tracheoblast or tracheole cell. It has several intracellular tubular extensions called tracheoles. Tracheoles are devoid of intima and taenidia. They are formed of a protein called tracheal. Tracheolar fluid is present inside the tracheoles. The level of the tracheal fluid varies with the metabolic activity of the insect. It is more when the insect is inactive and completely reabsorbed into the tissues when the insect is more active. Tracheoles penetrate the cell and are intimately associated with mitochondria (to supply oxygen to them).

Question 4.
Describe the reproductive system of Periplaneta and draw neat and labelled diagrams of it.
Answer:
Periplaneta is dioecious, or unisexual and both the sexes have well-developed reproductive organs. Sexual dimorphism is evident both externally and internally. The female is different. The female is different from the male in respect of short and broad abdomen, presence of brood pouches, and absence of anal styles.

Male Reproductive system: The male reproductive system consists of a pair of testes. These are elongated and lobed structures lying on each lateral side in the fourth to sixth abdominal segments. They are embedded in the fat bodies. From the posterior end of each testis, there starts a thin duct, the vas deferens, the two vasa deferentia run backward and inwards to open into a wide median duct, the ductus ejaculators in the seventh segment. A characteristic mushroom-shaped gland is present in the 6th and 7th abdominal segments which functions as an accessory reproductive gland.

The gland consists of two types of tubules or i, long slender tubules, the utriculi majores or periphera tubules in short tubules, the utriculi breviores secretion of utriculi majores forms the inner layer of the spermatophore while that of utriculi breviores nourishes the sperms. These tubules open into the anterior part of the ejaculatory duct. The seminal vesicles are present on the ventral surface of the ejaculatory duct. These sacs store the sperms in the form of bundles called spermatophores. The ejaculatory duct is a muscular tube that extends posteriorly and opens at the gonopore or the male genital pore.

Female reproductive system: The female reproductive system of Periplaneta consists of a pair of ovaries, a pair of oviducts, vagina, spermathecae, spermathecal papilla, and colleterial glands.

Ovaries: A pair of large ovaries lie laterally in 2 to 6 abdominal segments. They are light yellow in colour surrounded by fat bodies. Each ovary consists of eight tubules called ovarian tubules or ovarioles. Each ovariole consists of a tapering anterior filament germarium and a posterior wider vitellarium. The germarium contains various stages of developing ova and the vitellarium contains mature ova with the yolk.

The tapering ends of the ovarioles of each ovary unite-to form a single thread that attaches to the dorsal body wall. The ovarioles, at their posterior end, unite to form a short wide oviduct. The oviduct unite to form a very short median vagina. The vertical opening of the vagina is called the female genital pore. It opens into a large genital pouch on the eighth sternum. A spermatheca or receptaculum seminis. Consisting of a left-sac-like and a right filamentous caecum is present in the 6th segment which opens by a median aperture on a small spermathecal papilla in the dorsal wall of the genital pouch on the ninth sternum.

In a fertile female, the spermatheca contains spermatophores obtained during copulation. A pair of branched colleterial glands is present behind the genital pouch separately just above the spermathecal aperture, secretion of the two collateral glands forms a hard egg case called ootheca a round the eggs.

Three pairs of a plate-like chitinous structure called gonapophyses are present around the female genital aperture. These gonapophyses guide the ova into ootheca as ovipositors. These are the female external genitalia.

Andhra Pradesh BIEAP AP Inter 1st Year Zoology Study Material Lesson 6 Biology in Human Welfare Textbook Questions and Answers.

AP Inter 1st Year Zoology Study Material Lesson 6 Biology in Human Welfare

Very Short Answer Type Questions

Question 1.
Define parasitism and justify this term.
Answer:
An intimate association between two organisms of different species in which ‘one is benefited and the other one is often adversely affected’ is called parasitism. The word parasitism comes from the Greek word ‘parasitos’ (Para-at the side of Sitos – food or grain) which means one eating at another one’s table.

Question 2.
Distinguish between a vector and a reservoir host.
Answer:

Question 3.
Distinguish between mechanical vector and biological vector.
Answer:

Question 4.
What is a hyperparasite? Mention the name of one hyper-parasite.
Answer:
A parasite that parasitizes another parasite is called a Hyper parasite.
Ex: Nosema notabilis (a cnidosporan) is a parasite in Sphaerospora polymorpha (a cnidosporan parasite in the urinary bladder of the toadfish).

Question 5.
What do you mean by parasitic castration? Give one example.
Answer:
Some parasites cause the degeneration of gonads of the host making it sterile. This effect is called parasitic castration.
eg: Sacculina (root-headed barnacle, a crustacean) causes the degeneration of ovaries in the crab Carcinus maenas.

Question 6.
What are the endo-parasitic adaptations observed in Fasciola hepatica?
Answer:
The life cycle of Fasciola hepatica (sheep liver fluke) is very complex involving many developmental stages and two intermediate hosts to increase the chances of reaching a new definitive host.

Question 7.
Define Neoplasia. Give one example.
Answer:
Some cause abnormal growth of the host cells in a tissue to form new structures. This effect is called Neoplasia which leads to cancers.
Ex: Some Viruses.

Question 8.
Define the most accurate definition of the term ‘health’ and write any two factors that affect health.
Answer:
Health is a state of complete physical, mental and social well-being and not merely the absence of any disease or absence of physical fitness. Our health may be affected by crenetic disorders, infections, and lifestyle.

Question 9.
Distinguish between infectious and non-infectious diseases. Give two examples each.
Answer:

Question 10.
Entamoeba histolytica is an obligatory anaerobe justify.
Answer:
Mitochondria is absent in the endoplasm of Entamoeba histolytica. The absence of mitochondria indicates the obligate anaerobic nature of Entamoeba histolytica.

Question 11.
Distinguish between the precystic stage and the cystic stage of E.histolytica.
Answer:

Question 12.
What is the reserve food in the precystic and early cyst stages of Entamoeba histolytica?
Answer:
The cytoplasm of the precystic stage stores glycogen granules and chromatoid bars (made of ribonucleic protein) which act as reserve food.

Question 13.
A person is suffering from bowel irregularity, abdominal pain, blood and mucus in stool, etc. Based on these symptoms, name the disease and its causative organism.
Answer:

• The disease is Amoebiasis.
• The causative agent is the Trophozoite of “Entamoeba histolytica”.

Question 14.
On the advice of a doctor, a patient has gone to a clinical laboratory for the examination of a sample of faeces. The lab technician, on observing the stool of the patient diagnosed that the patient was suffering from amoebiasis. Write any two characteristic features based on which the technician came to that conclusion.
Answer:

1. Stool with blood and mucous.
2. Presence of a tetra nucleated cyst.

Question 15.
Define ‘asymptomatic cyst passers’ with reference to Entamoeba histolytica.
Answer:
Some people do not exhibit any symptoms, such people are called carriers of asymptomatic cyst passers as their stand contains the tetranuclear cysts. They help in spreading the parasites to their persons.

Question 16.
What are the stages of plasmodium vivax that infect the hepatocytes of man?
Answer:
Sporozoite, Cryptozoite, Macrometacryptozoite.

Question 17.
Define the prepatent period. What is its duration in the life cycle of plasmodium vivax?
Answer:
The interval between the first entry of plasmodium into the blood in the form of sporozoites and the second entry of plasmodium into the blood in the form of Cryptozoics is called a prepatent period. It lasts approximately 8 days.

Question 18.
Define incubation period. What is its duration in the life cycle of Plasmodium vivax?
Answer:
The period between the entry of Plasmodium into the blood in the form of sporozoite and the first appearance of symptoms of malaria in man is called the incubation period which is approximately 10 to 14 days.

Question 19.
What are Schuffner’s dots? What is their significance?
Answer:
Small red coloured dots appear in the cytoplasm of the RBC known as Schuffner’s dots. These are believed to be the antigens released by the plasmodium (Malaria) parasites.

Question 20.
What are hemozoin granules? What is their significance?
Answer:
The malaria parasite digests the globin part of the ingested hemoglobin and converts the soluble heam into insoluble crystalline hemozoin. It is called the ‘malaria pigment’ which is a disposable product.

Question 21.
What is exflagellation and what are the resultant products called?
Answer:
Male gapnetes show lashing movements like flagella and get separated from the cytoplasm of microgametocyte. This process is called exflagellation and resultant products are called male (or) microgametes.

Question 22.
Why is the syngamy found in plasmodium called anisogamy?
Answer:
Since two gametes are dissimilar in size, the syngamy found in plasmodium is called anisogamy.

Question 23.
What is Ookinete? Based on the sets of chromosomes how do you describe it?
Answer:
Ookinete is a long, splendor, motile, vermiform, two sets of chromosomes are present in it. So it is described as diploid form.

Question 24.
A person is suffering from chills and shivering and high temperature. These symptoms are cyclically followed by profuse sweating and a return to normal body temperature. Based on these symptoms name the disease and its causative organism.
Answer:
The disease is malaria and the causative organism is Plasmodium vivax.

Question 25.
Describe the methods of biological control of mosquitoes.
Answer:
Introduction of larvivorous fishes like Gambusia, and insectivorous plants like Utricularia into the places where mosquitoes breed.

Question 26.
The eggs of Ascaris are called “mammillated eggs”. Justify it.
Answer:
Each egg of Ascaris is surrounded by a protein coat with a rippled surface. Hence the eggs of Ascaris are called “mammilated eggs”.

Question 27.
What is meant by nocturnal periodicity with reference to the life history of a nematode parasite you have studied?
Answer:
Microfilaria larvae of W.brancrofti migrate to the peripheral blood circulation during nighttime between 10 P.M – 4 A.M. This tendency is called nocturnal periodicity.

Question 28.
Distinguish between lymphadenitis and lymphangitis.
Answer:

Question 29.
‘Elephantiasis is the terminal condition of filariasis’. Justify.
Answer:
Sweat glands of the skin in the affected region disintegrate and skin becomes rough so elephantiasis is the terminal condition of filariasis.

Question 30.
In which way does tobacco affect respiration? Name the alkaloid found in tobacco.
Answer:
Tobacco increases the carbon monoxide (CO) level and reduces the oxygen level in the blood. The alkaloid found in tobacco is “Nicotine”.

Question 31.
Define drug abuse.
Answer:
When drugs are used for a purpose other than medicinal use is called drug abuse.

Question 32.
From which substances ‘Smack’ and ‘coke’ are obtained?
Answer:
Smack is the common name for “Heroine”. It is obtained from the opium poppy plant. (Papaver somniferum).
Coke is the common name for “Cocaine”. It is obtained from the coca plant (Erythroxylum coca).

Question 33.
‘Many secondary metabolites of plants have medicinal properties. It is their misuse that creates problems. justify the statement with an example.
Answer:
Many secondary metabolites of plants like opioids, cannabinoids, and coca alkaloids are abused nowadays. Even though they have medicinal properties they cause some effects.

Question 34.
Why are cannabinoids and anabolic steroids banned in sports and games?
Answer:
These days some sports persons take drugs such as cannabinoids and anabolic steroids to enhance their performance (Doping) and abuse of such drugs also causes side effects that’s why such drugs are banned in sports and games.

Question 35.
Mention the names of any four drugs which are used as medicines to treat patients with mental illnesses like depression, insomnia, etc., that are often abused.
Answer:
Barbiturates, Amphetamines, Benzodiazepines, Lysergic aciddiethyl amides (LSD).

Short Answer Type Questions

Question 1.
What is the need for parasites to develop special adarptations? Mention some special adaptations developed by the parasites.
Answer:
Parasites have to evolve mechanisms to counteract and neutralize the host’s defence in order to be successful within the host. For this purpose, the parasites have developed many special adaptations such as the loss of unnecessary sensory organs, formation of organs for adhesion, high reproductive capacity, etc.
Parasitic adaptations: Parasites have evolved special adaptations to meet the requirements and lead successful lives in the hosts.

• In order to live in the host, some parasites have developed structures like hooks, suckers, rostellum, etc., for anchoring, e.g: Taenia solium.
• Some intestinal parasites have developed protective cuticles to withstand the action of the digestive enzymes of the host, e.g: Ascaris lumbricoides.
• Some intestinal parasites produce anti enzymes to neutralize the effect of the host’s digestive enzymes, e.g: Taenia solium.
• Some parasites live as obligatory anaerobes as the availability of oxygen is very rare for them, e.g: Entamoeba histolytica, Taenia solium, etc.
• Some intestinal parasites live as facultative anaerobes, i.e., if oxygen is not available, they live anaerobically and if oxygen is available, they respire aerobically, e.g: Ascaris lumbricoides.

Question 2.
Distinguish between hypertrophy and hyperplasia with an example for each.
Answer:

Question 3.
Describe the structure of a trophozoite of Entamoeba histolytica.
Answer:
It is the most active, motile, feeding, and pathogenic stage that lives in the mucosa of the large intestine. It moves with the help of pseudopodium (lobopodium) which is produced anteriorly. The body of the trophozoite is surrounded by plasmalemma. Its cytoplasm is differentiated into an outer clear, viscous, non-granular ectoplasm and inner fluid-like granular, endoplasm.

Ribosomes, food vacuoles, and verticular cartwheel-shaped nucleus is present Absence of mitochondria indicates the obligate anaerobic nature of Entamoeba histolytica. It produces a proteolytic enzyme called histolytica which dissolves mucosas & sub-mucosa of the gut wall & releases blood, and tissue debris which are ingested by the trophozoite.

Hence food vacuoles are loaded with R.B.C & fragments of cells, and bacteria. The presence of R.B.C in the food vacuole and cart wheel-shaped nucleus are the characteristic features of the trophozoite.

Question 4.
Explain the life cycle of Entamoeba histolytica.
Answer:
The trophozoite undergoes binary fissions in the wall of the large intestine and produces a number of daughter entamoeba. They feed upon the bacteria and the hostly tissue elements, grow in size, and again multiply. After repeated binary fissions some of the young ones enter the lumen of the large intestine and transform into precystic stage.

Here, the precystic stage transforms into the cystic stage. Which in turn develops into tetranuclear cysts. The entire process is completed only in a few hours. These tetra nucleated cysts come out along with the faecal matter and can remain alive for about 10 days. These cysts reach new hosts through contaminated food and water. They pass into the small intestine of a new human host. Where the cyst wall gets, ruptured by the action of the enzyme trypsin releasing tetra nucleated amoeba. Such tetra nucleated exocyst amoeba is called metacyst. The four nuclei of the metacyst undergo mitotic divisions and produce eight nuclei. Each nucleus gets a bit of cytoplasm and thus eight daughter entamoeba are produced. The young ones develop into trophozoites and invade the large intestine.

Question 5.
Write a short note on the pathogenicity of Entamoeba histolytica.
Answer:
The trophozoites ‘dissolve’ the mucosal lining by histolysin going deep into the submucosa and causing ulcers. These ulcers contain cellular debris, lymphocytes, blood corpuscles, and bacteria. It leads to the formation of abscesses in the wall of the large intestine. Ultimately it results in stools with blood and mucous. This condition is called amoebic dysentery (or) Intestinal amoebiasis. Some people don’t exhibit any symptoms such people are called ‘carriers’ (or) asymptomatic cyst passers as their stools contain tetranucleotide cysts.

Question 6.
Describe the structure of the sporozoite of plasmodium vivax.
Answer:
The ultrastructure of the sporozoite of P. vivax was studied by barnham. It is sickle-shaped with a swollen middle part and pointed at both ends of it’s body. It measures about 15 microns in length and one micron in width. The body is covered by an elastic pellicle with microtubules which help in the curiggling movement of the sporozoite. The cytoplasm contains cell organelles such as the Golgi complex, E.R. mitochondria, and a nucleus.

The cytoplasm also shows many convoluted tubules of unknown function throughout the body. It contains a cup-like depression called an apical cup at the anterior end into which a pair of secretory organelles opens. They secrete a cytolytic enzyme which helps in the penetration of sporozoite into the liver cell.

Question 7.
Describe the cycle of Golgi in the life history of Plasmodium Vivax.
Answer:
It was first described by Camillo Golgi. Hence it is also called the Golgi cycle. This is initiated either by the trophozoites of the pre-erythrocytic cycle (or) the micro meta cryptozoites of the exo-erythrocytic cycle. In the fresh R.B.C, these stages assume the spherical shape and transform into trophozoite. It develops a small vacuole that gradually enlarges in size, and pushes the cytoplasm and nucleus to the periphery.

Now the plasmodium looks like a finger ring. Hence this stage is called the signet ring stage soon it loses the vacuole, develops pseudopodia, and becomes an amoeboid stage. With the help of pseudopodium, it actively feeds on the content of the R.B.C and increases in size. As a result, the R.B.C grows almost double the size. This process is called hypertrophy. The malaria parasite digests the globin part of the ingested hemoglobin and converts the soluble haem into insoluble Haemozine. It is called malaria pigment. During this stage, small red coloured dots appear in the cytoplasm of R.B.C known as “Schuffner’s dots’.

Now the parasite loses the pseudopodia and increases in size finally it occupies the entire R.B.C and becomes schizont. It undergoes schizogony and produces 12-24 erythrocytic merozoites. They are arranged in the form of a rose hence this stage is called the rosette stage. Finally, merozoites are released along with haemozoine into the blood.

Question 8.
Explain the pathogenicity of Wucheria bancrofti in Man.
Answer:
The infection causes filarial fever which is characterized by headache, mental depression, and an increase in the body temperature. In general, the infection of filarial worm causes inflammation effect in lymph vessels and lymph glands. Inflammation in the lymph vessels is called lymphangitis and that of lymph glands is called lymphadenitis. In the case of heavy infection, the accumulation of dead worms blocks the lymph vessels and lymph glands resulting in immense swelling of limbs, scrotum of males, and mammary glands in females. Fibroblasts accumulate in this tissue and form the fibrous tissue. In severe cases, the sweat glands of the skin in the affected region disintegrate and the skin becomes rough. This terminal condition is called elephantiasis.

Question 9.
Write short notes on typhoid fever and its prophylaxis.
Answer:
Typhoid fever: It is caused by salmonella typhi which is a gram-negative bacterium. It mainly lives in the small intestine of man and then migrates to other organs through blood. It can be confirmed by the Widal test.
Mode of infection: Contamination through food and water.
Symptoms: Sustained fever with high temperature upto 104°F. weakness, stomach pain, constipation, headache, and loss of appetite. Intestinal perforation and death may also occur in severe cases.
Prophylaxis: Advancements made in biological science have armed us to deal with many infections effectively. The immunization programme by the use of vaccines has enabled us to completely irradicate like typhoid. Biotechnology is making available never cheaper vaccines, and the discovery of antibiotics and various other drugs also enabled us to treat typhoid.

Question 10.
Write short notes on Pneumonia and its prophylaxis.
Answer:
Pneumonia: It is caused by gram-positive bacteria such as Streptococcus pneumonia and Haemophilus influenza. They infect the alveoli of the lungs in human beings.
Mode of infection: Contamination by inhaling the droplets/aerosols released by an infected person or even by sharing the utensils with an infected person.
Symptoms: The alveoli get filled with fluid leading to severe problems in respiration. In severe cases, the lips and fingernails may turn gray to bluish in colour.
Prophylaxis: Advancements made in biological science have armed us to deal with many infections effectively. The immunization programme by the use of vaccines has enabled us to completely irradicate pneumonia. Biotechnology is making available newer, cheaper vaccines, and the discovery of antibiotics and various other drugs also enabled us to treat pneumonia.

Question 11.
Write short notes on the common cold and its prophylaxis.
Answer:
Common cold: It is caused by a rhinovirus group of viruses. They infect the nose and respiratory passage but not the lungs.
Mode of infection: Contamination is by direct inhalation of the droplets resulting from cough or sneezes of an infected person or indirectly through contaminated objects such as pens, books, cups, door knobs, computer keyboards or mice, etc.
Symptoms: Nasal congestion, discharge from the nose, sore throat, hoar senses, cough, headache, tiredness, etc., which usually last for 3-7 days.
Prophylaxis: Advancements made in biological science have armed to deal with many infections effectively. The immunization programme by the use of vaccines has enabled us to completely irradicate like viral diseases common cold. Biotechnology is making available newer cheaper vaccines, the discovery of antibiotics and various other drugs also enabled use to treat viral diseases like the common cold.

Question 12.
Write short notes on ‘ringworm’ and its prophylaxis.
Answer:
Ringworm: It is one of the most common infectious diseases in man. It is caused by many fungi belonging to the genera, Microsporum, Trichophyton, and Epidermophyton. Heat and moisture help these fungi grow in the skin folds such as those in the groin or between the toes.
Mode of infection: Contamination is by using towels, clothes or combs of the infected persons or even from the soil.
Symptoms: Appearance of dry, scaly, usually round lesions accompanied by intense itching on various parts of the body such as skin, nails, and scalp.

Question 13.
What are the adverse effects of tobacco?
Answer:
Effect: Smoking increases the carbon monoxide (CO) level and reduces the oxygen level in the blood. Nicotine stimulates the adrenal gland to release adrenaline and nor-adrenaline into the blood. These hormones raise blood pressure and increase the heart rate. Smoking is associated with bronchitis, emphysema, coronary heart disease, and gastric ulcer and increases the incidence of cancers of the throat, lungs, urinary bladder, etc. Smoking also paves the way to hard drugs. Yet smoking is very prevalent in society, both among young and old-. Tobacco chewing is associated with an increased risk of cancer of the oral cavity.

Question 14.
Write short notes on opioids.
Answer:
Opioids: These are the drugs obtained from the opium poppy plant Papaver somniferous (vernacular name: Nallamandu mokka): They bind to specific opioid receptors present in our central nervous system and gastrointestinal tract. Some of them are morphine, heroin, etc.
Morphine: It is extracted from the dried latex of the unripe seed capsule (Pod) of the poppy plant. It occurs as colourless crystals or a white crystalline powder.
Mode of abuse: Generally it is taken orally or by injection.
Effect: It is effective as a sedative and painkiller. It is very useful in patients who have undergone surgery.
Heroin: It is a white, bitter, odourless, and crystalline compound, obtained by the acetylation of morphine. Chemically it is diacetylmorphine. It is commonly called a snack.
Mode of abuse: Generally it is taken by shorting and injection.
Effect: Heroin is a depressant and slows down body functions.

Question 15.
Write short notes on Cannabinoids.
Answer:
Cannabinoids: These are a group of chemicals obtained from the Indian temp, plant cannabis Sativa (vernacular name Ganjai mokka). They interact with cannabinoid receptors present in the brain. The flower tops, leaves, and the resin of this plant are used in various combinations to produce marijuana, hashish, charas, and ganja. These daufs, cannabinoids are being abused by even some sports – persons (doping).
Mode of abuse: These are generally taken by inhalation and oral ingestion.
Effect: Show their effects on the cardiovascular system of the body.

Question 16.
Write short notes on Cocaine.
Answer:
Coca alkaloid or cocaine: It is a white, crystalline alkaloid that is obtained from the leaves of the coca plant Erythroxylum coca, native to South America. It is commonly called coke or crack.
Mode of abuse: It is usually shorted.
Effect: It has a potent stimulating action on the central nervous system as it interferes with the transport of the neurotransmitter dopamine. Hence it produces a sense of euphoria and increased energy. Its excessive dosage causes hallucinations.

Question 17.
Why adolescence is considered a vulnerable phase?
Answer:
Adolescence: It is the time period between the beginning of puberty and the beginning of adulthood. In other words. It is the bridge linking childhood and adulthood. The age between 12-18 years is considered adolescence period. It is both a period and process during which a child becomes muture. It is accompanied by several biological and behavioural changes. Thus, adolescence is a very vulnerable phase of the mental and psychological development of an individual.

Question 18.
Distinguish between addiction and dependence.
Answer:
Addiction: It is a psychological attachment to certain effects such as euphoria. The most important thing one fails to realize it, the inherent addictive nature of tobacco, drugs, and alcohol, with the repeated use of TDA, the tolerance level of the receptors present in our body increases. Consequently, the receptors respond only to higher doses leading to greater intake and addiction. However, it should be clearly borne in mind that the use of TDA even once, can be a forerunner to addiction. Thus, the addictive potential of tobacco, drugs, and alcohol pull the users into a vicious circle leading to their regular use (abuse) from which they may not be able to get out. In the absence of any guidance or counseling, people get addicted and become dependent on them.

Dependence: It is the tendency of the body of manifest a characteristic unpleasant condition (withdrawal syndrome). The regular dose of drugs or alcohol is abruptly discontinued. The withdrawal syndrome is characterized by anxiety. Shakiness (tremors), nausea, and sweating may be relieved when regular use is resumed again. Dependence leads the patients to ignore all social norms.

Question 19.
‘Prevention is better than cure. justify with regard to TDA abuse.
Answer:
The age-old adage of prevention is better than cure holds true here also.
Some of the measures successful in the prevention and control of TDA abuse among adolescents are:

• Avoid undue parental pressure: Every child has his/her own choice. Capacity and personality. Parents should not force their children to perform beyond their capacity by comparing them with others in studies, games, etc.
• Responsibility of parents and teachers: They should look for the danger signs and counsel such students who are likely to get into the ‘trap’.
• Seeking help from peers: If peers find someone abusing drugs or alcohol immediately it should be brought to the notice of their parents or teachers so that they can guide them appropriately.
• Education and counseling: Educating and counseling the children to face problems, stress, and failures as a part of life.
• Seeking professional and medical help: A lot of help is available in the form of highly qualified psychologists, psychiatrists, and de-addiction and rehabilitation programmers.

Long Answer Type Questions

Question 1.
Explain the structure and life cycle of Entamoeba histolytica with the help of neat and labelled diagrams.
Answer:
Entamoeba histolytica (Gr. entos – within : amoiba – change histos – tissues ; lysis – dissolve) is a microscopic and monogenetic parasite that inhabits the large intestine and causes amoebic dysentery or amoebiasis in man.

It is cosmopolitan in distribution but more common in the tropical and subtropical regions of the world. It is common in the people of rural and densely populated urban areas wherever the hygienic conditions are poor.

Structure: Entamoeba histolytica passes through three distinct stages in its life cycle namely

• Trophozoite stage
• Precystic stage
• Cystic stage

(i) Trophozoit stage: It is the most active, motile, feeding, and pathogenic stage that lives in the mucosa and sub-mucosa membrane of the large intestine; It moves with the help of a lobopodium which is produced anteriorly. The body of the trophozoite is surrounded by plasma-lemma. Its cytoplasm is differentiated into outer clear, viscous non-granular ectoplasm and inner fluid like granular endoplasm.

Ribosomes, food vacuoles, and vesicular, cartwheel-shaped nuclei are present in the endoplasm. The absence of mitochondria indicates the obligate anaerobic nature of Entamoeba histolytica. It produces the proteolytic enzyme called histolysis due to which the species name histolytica was assigned to it. Due to the effect of this enzyme the mucosa and submucosa of the gut wall are dissolved releasing some amount of blood, and tissue debris that are ingested by the trophozoites. Hence the food vacuoles are with erythrocyte fragments of epithelial cells and bacteria. The presence of RBC in food vacuoles and cartwheel-shaped nuclei are the characteristic features of the trophozoites of Entamoeba histolytic.

(ii) Precystic stage: It is the non-feeding and non-pathogenic stage of Entamoeba histolytica that is found in the lumen of the large intestine. It is a small, spherical, or oval, non-motileform. The cytoplasm of the precystic stage stores glycogen granules and chromatid bars (made of ribonucleic protein) which act as reserve food.

(iii) Cystic stage: It is round in shape and is surrounded by a thin, delicate, and highly resistant cyst wall. It is found in the lumen of the large intestine. The process of development of the cyst wall is called encystation. Which is a means of tiding over the un¬favourable conditions that the parasite is going to encounter while passing to a new host. Soon after the encystation, the nucleus undergoes two successive mitotic divisions to form four daughter nuclei. This type of cystic stage is called tetranuclear cyst or mature cyst which is the stage infective to man.

Life cycle: The trophozoites undergo binary fissions in the wall of the large intestine and produce a number of daughter entamoeba. They feed upon the bacteria and the host’s tissue elements, grow in size, and again multiply. After repeated binary fission some of the young ones enter of the lumen of the large intestine and transform into precystic stages. Here, the precystic stages transform into cystic stages which in turn develop into tetranuclear cysts. The entire process is completed only in a few hours. These tetranuclear cysts come out along with the faecal matter and can remain alive for about 10 days. The cyst reaches a new host through contaminated food and water. In the small intestine of a new human host, the cyst wall gets ruptured releasing the tetranuclear amoebae. Such tetranuclear excystic amoebae are called metacysts.

The four nuclei of the metacyst undergo mitotic divisions and produce eight nuclei. Each nucleus gets a bit of the cytoplasm and thus eight daughter entamoeba or metacystic trophozoites are produced. These young ones develop into feeding stages called trophozoites. They invade the mucous membrane of the large intestine and grow into mature trophozoites.

Question 2.
Describe the life cycle of plasmodium vivax in man.
Answer:
The life cycle of plasmodium in man (The human phase): In man, the plasmodium reproduces by asexual reproduction called schizogony. It occurs in liver cells (hepatocytes) as well as in RBC. In liver cells, it is called hepatic schizogony and in RBC it is called erythrocytic schizogony.

Hepatic Schizogony: This was discovered by short and Cranham. Whenever a mosquito infected by plasmodium bites a man, nearly 2000 sporozoites are released into the blood of man through its saliva, within half an hour, they reach the hepatocytes where they undergo pre-erythrocytic and exo-erythrocytic cycles.

Pre-erythrocytic cycle: Whenever the sporozoites enter the liver cells they transform into trophozoites. They feed on the contents of the hepatic cells, assume a spherical shape, and attain the maximum size. This stage is called the schizont stage. Its nucleus divides several times Mitotically, followed by the cytoplasmic divisions resulting in approximately 12,000 daughter individuals called cryptozoites or the 1st generation merozoites. They enter the sinusoids of the liver by rupturing the cell membrane of the schizont and the liver cells. This entire process is completed approximately in 8 days. Now, these first-generation merozoites have two options, i.e., they can enter either fresh liver cells and continue the exo-erythrocytic cycle or they can enter RBC and continue the erythrocytic cycle.

Exo-erythrocytic cycle: If the trophozoites enter the fresh liver cells, they undergo changes similar to that of the pre-erythrocytic cycle and produce the second generation merozoites called meta cryptozoites. These are of two types the smaller micro-metacryptozoites and larger macro-metacry- photosites. This entire process is completed approximately in two days. The macro-metacryptozoites attack fresh liver cells and continue another exo-erythrocytic cycle, whereas the micro-metacryptozoites always enter the bloodstream and attack fresh RBC to continue the erythrocytic cycle.

Prepatent period: The interval between the first entry of plasmodium into the blood in the form of sporozoites and the second entry of plasmodium into the blood in the form of Cryptozoic is called a prepatent period. It lasts approximately 8 days. During this period, the host does not show any clinical symptoms of the disease. It is only a means of multiplication.

Erythrocytic cycle: It was first described by Camillo Golgi Hence it is also called Golgi cycle. This cycle is initiated either by the trophozoites of the pre-erythrocytic cycle or the micro metocryptozoites of the exo-erythrocytic cycle in the fresh RBC, these stages assume the spherical shape and transform into trophozoites. It develops a small vacuole that gradually enlarges in size pushing the cytoplasm and nucleus to the periphery.

Now the plasmodium looks like a fisher ring. Hence this stage is called the signet ring stage. Soon it loses the vacuole, develops pseudopodia, and becomes an amoeboid stage with the help of pseudopodia. It actively feeds on the contents of the RBC and increases in size. As a result, the RBC grows almost double its size. This process is called hypertrophy. The malaria parasite digests the globin part of the ingested hemoglobin and converts the soluble haem into insoluble crystalline haemozoin. It is called the ‘malaria pigment’ which is called a disposable product. During this stage, small red coloured dots appear in the cytoplasm of the RBC known as Schaffner’s dots. These are believed to be the antigens released by the parasite.

Now the plasmodium loses the pseudopodia, further increases in size, occupies the entire RBC, and becomes a schizont. It undergoes schizogony similar to that of the pre-erythrocytic cycle and produces 12 to 24 erythrocytic merozoites. They are arranged in the form of the petals of a rose in the RBC. Hence this stage is called the rosette stage] Finally the erythrocyte bursts and releases the merozoites along with haemozoin into the blood. This cycle is completed approximately in 48 hours.

Incubation period: The period between the entry of plasmodium into the blood in the form of sporozoite and the first appearance of symptoms of malaria in man is called the incubation period, which is approximately 10 to 14 days.

Formation of gametocytes: After repeated cycles of erythrocytic schizogony when the number of fresh RBC decreases, some merozoites enter the RBC and transform into gametocytes instead of continuing the erythrocytic cycle. This process generally takes place when the RBCs are present in the spleen and bone marrow.

The gametocytes are of two types namely smaller microgametocytes or male gametocytes and larger macrogametocytes or female gametocytes. The gametocytes cannot undergo further development in man as the temperature and PH of the blood man are not suitable for further development. These gametocytes reach the blood circulation and wait to reach the next host. They degenerate and die if they are not transferred to mosquitoes within a week.

Question 3.
Describe the life cycle of plasmodium vivax in mosquitoes.
Answer:
Life cycle of plasmodium in mosquito (The mosquito phase) Ross cycle: When a female Anopheles mosquito bite and sucks the blood of a malaria patient the gametocytes along with the other stages of the erythrocytic cycle reach the crop of mosquito. Here all the stages are digested except the gametocytes. Further part of the life cycle consists of

• Gametogony
• Fertilization
• Formation of ookinete & oocysts
• Sporogony

(i) Gametogony: The formation of male and female gametes from the gametocytes is called gametogony. It occurs in the lumen of the crop of mosquitoes.

Formation of male gametes: During this process, the nucleus of the microgametocyte divides into eight daughter nuclei called pronuclei which reach the periphery. The cytoplasm is pushed out in the form of eight flagella-like processes. Into each flagellum-like process, one pronucleus enters and forms a micro gamete or male gamete. These male gametes show lashing movements like flagella and get separated from the cytoplasm of microgametocyte. This process is called exflagellation.

Formation of female gamete: The female gametocyte undergoes a few changes and transforms into a female gamete. This process is called maturation. The nucleus of the female gamete moves towards the periphery and the cytoplasm at that point forms a projection. This projected region is called the fertilization cone.

Fertilization: The fusion of male and female gametes is called fertilization. It also occurs in the lumen of the crop of the mosquito. When an actively moving male gamete comes into contact with the fertilization cone of the female gamete, it enters it, and the pronuclei and cytoplasm of these two gametes fuse with each other, resulting in the formation of a synkaryon Since the two gametes are dissimilar in size this process is known as anisogamy. The female gamete that bears the synkaryon is called the zygote which is round and non-motile.

(iii) Formation of ookinete and oocysts: The zygote remains inactive for some time and then transforms into a long, slender, motile, vermiform ookinete or vermicule within 18 to 24 hours. It pierces the wall of the crop and settles beneath the basement membrane. It becomes round and secretes a cyst around its body. This encysted ookinete is now called an oocyst. About 50 to 500 oocysts are formed on the wall of the crop and appear in the form of small nodules.

(iv) Sporogony: The formation of sporozoites in the oocysts is called sporogony. According to Bano, the nucleus of the oocyst first undergoes reduction division followed by repeated mitotic divisions resulting in the formation of about 1,000 daughter nuclei. Each bit of the nucleus is surrounded by a little bit of the cytoplasm and transforms into a sickle-shaped sporozoite. Oocyst with such sporozoites is called sporocyst.

When this sporocyst raptures, the sporozoites are liberated into the haemocoel of the mosquito. From there, they travel into the salivary glands and are ready for infection. The life cycle of plasmodium in mosquitoes completes in about 10 to 24 days.

Question 4.
Describe the structure and life cycle of Ascaris lumbricoides with the help of a neat and labelled diagram.
Answer:
Ascaris lumbricoides is commonly called the common roundworm. It lives in the small intestine of man, more frequently in children. It is cosmopolitan in distribution. The mode of infection is through contaminated food and water. The infective stage is the embryonated: egg with the 2nd stage rhabditiform larva.

Structure: Sexes are separate and sexual dimorphism is distinct. In both males and females, the body is elongated and cylindrical. The mouth is present at the extreme anterior end and is surrounded by three chitinous lips close to the mouth. Mid ventrally there is a small aperture called an excretory pore.

Male: It has a curved posterior end which is considered the tail. The posterior end possesses a cloacal aperture and a pair of equal-sized chitinous pineal spicules or pineal setae which serve to transfer the sperms during copulation.

Female: It has a straight posterior end, the tail. The female genital pore or vulva is present mid-ventrally at about one-third the length from the mouth. The anus is present a little in front of the tail end.

Life history: Copulation takes place in the small intestine of a man. After copulation, the female releases approximately two lakh eggs per day. Each egg is surrounded by a protein coat with a rippled surface. Hence the eggs of Ascaris are described as mammilla eggs. The protein coat is followed by a chitinous shelf and a lipid layer internally. These eggs come out along with faecal matter. In the moist soil, development takes place inside the egg so that the 1st stage rhabditiform larva is produced. It undergoes the 1st moulting and becomes the 2nd stage rhabditiform larva which is considered the stage infective to man. They reach the alimentary canal of man through contaminated food and water.

In the small intestine, the shell gets dissolved so that the 2nd stage larva is released. Now it undergoes extra-intestinal migration. First, it reaches the liver through the hepatic portal vein. From there it reaches the heart through the post caval vein. It goes to the lungs through the pulmonary arteries.

In the alveoli of the lungs, it undergoes the 2nd moulting to produce the 3rd stage larva. It undergoes the 3rd moulting so that the 4th stage larva is produced in the alveoli only. It leaves the alveoli and reaches the small intestine again through the bronchi, trachea, larynx, glottis, pharynx, oesophagus, and stomach. In the small intestine. It undergoes the 4th and final moulting to become a young one which attains sexual maturity within 8 to 10 weeks.

Question 5.
Describe the life cycle of wucheria bancrofti.
Answer:
Wucheria bancrofti is commonly called the filarial worm as it causes filariasis in human beings. It is a digenetic parasite that lives in the lymph vessels of man. Sir Patrick Manson identified the female culex mosquito as its secondary host.

Life cycle: It completes its life cycle in two hosts namely man and female culex mosquito.

In man: Both male and female worms are found coiled together in the lymphatic vessels of man. After copulation, the female releases the sheathed microfilaria larvae into the lymph of the man. Each sheathed microfilaria larva measures 0.2 to 0.3 mm in length. It is surrounded by a loose cuticular sheath which is supposed to be the modified shell. They migrate to the blood circulation and reside in the deeper blood vessels during the daytime. They move to the peripheral blood circulation during the nighttime between 10.00 pm and 4.00 am. This tendency is referred to as nocturnal periodicity. When a female culex mosquito sucks the blood of an infected person. They enter the gut of mosquitoes. They die if they are not transferred to mosquitoes within 70 days.

In mosquito: In the midgut of a mosquito, the sheath of the larva is dissolved within 2 to 6 hours of the infection. The ex-sheathed microfilaria larva penetrates the gut wall and reaches the heamocoel of the mosquito. From there, it reaches the thoracic muscles and transforms into a sausage-shaped larva within two days. It is called the first stage larva or first stage microfilaria. This undergoes two moultings within 10 to 20 days and transforms into infective 3rd stage microfilaria. It reaches the labium of the mosquito.

In man after the infection: When an infected mosquito bites a man, the 3rd stage microfilaria larvae enter the blood circulation of the man and finally reach the lymphatic vessels. Here they undergo the 3rd and the 4th moultings to produce young filarial worms. They attain sexual maturity within 5 to 18 months.