AP State Syllabus AP Board 7th Class Science Solutions Chapter 10 Nutrition in Plants Textbook Questions and Answers.
AP State Syllabus 7th Class Science Solutions 10th Lesson Nutrition in Plants
7th Class Science 10th Lesson Nutrition in Plants Textbook Questions and Answers
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A potted plant is kept in light for a day and one of its leaves is tested for starch. The same plant is kept in the dark for two days and another leaf is tested for starch. Will there be a difference in the results of the two experiments? Give reasons for your answer.
- The leaves of the plant kept in light for a day are tested for starch.
- In the test it is found that the leaves contain starch.
- The leaf of the same plant when kept in dark for two days is tested for starch.
- In the test it is found that the leaf does not contain starch.
- Leaves of plant is the presence of sunlight prepare Glucose.
- This glucose is then converted into starch.
- In the absence of light plants cannot prepare glucose and then starch.
What happens if leaves of a green plant are coated with oil?
(Hint: What will be the effect on stomata ?)
- If leaves of a green plant are coated with oil the pores of the stomata which are useful for the exchange of gases from the atmosphere are covered with oil.
- When the pores of the leaves are thus covered by oil, the leaves fail to carry out photosynthesis.
- The plant therefore cannot prepare its own food through leaves.
Do you think saprophytes help us in keeping the environment clean?
(Hint: What do saprophytes feed on ?)
- Saprophytes feed on dead and decaying organism.
- So they help in keeping the environment clean.
Differentiate between following with some examples.
a) Parasite and saprophyte
b) Host and parasite
|1. A parasite takes food from the organism on which it lives.
|1. They secrete digestive juice on the matter they live and convert it into a solution and then absorb it.
|2. They feed on a living organism
|2. They feed on dead and decaying organism.
|3. The organism on which it feeds is called host.
|3. They do not feed on living organism.
|1. They prepare the nutrition.
|1. They get nutrition from the host.
|2. These plants produce their food.
|2. It takes food from the plant on which it is climbing.
|3. The leaves of the these plants will have chlorophyll.
|3. These have no leaves and chlorophyll.
Fill in the blanks and give reasons :
(i) Green plants are ………… in nature
(ii) The food synthesized by the plants is stored as …………
(iii) Saprophytes depend on ………… for food.
i) Autotrophs: Because green parts of a plant make glucose, starch, and other food materials
by the process, photosynthesis, using carbon dioxide in the presence of sunlight.
ii) starch: Starch is formed by combining carbon dioxide, water and light.
iii) dead and decaying matter: These types of plants do not contain chlorophyll so they simply absorb organic material from decaying matter.
Name the following:
a) Pores through which leaves exchange gases.
b) Plants that act as scavenger of nature.
c) Those plants that share food and shelter.
d) Plants which cannot make their own food and obtain it from host.
a) Stomata are the pores through which leaves exchange gases.
b) Saprophytes are the plants that act as scavenger of nature.
c) Host plants are those plants that share food and shelter.
d) Parasitic plants are the plants which cannot make their own food and obtain it from host.
Tick the correct answer
i) Cuscuta is an example of
A) Autotroph B) Parasite C) Saprophyte D) Symbiont
ii) Haustoria are
A) Roots B) Stems C) Leaves D) All of them
iii) Raw materials involved in the process of photosynthesis
A) Carbon dioxide B) Water C) Sun light D) All of them
D) All of them
Circle the insectivorous plant among the plants given below.
A) Hibiscus B) Teak C) Nepanthis D) Aloevera
Collect information about experiments of Joseph Priestly and Ingen Houz from Internet and make a brief note on them.
- It was Priestley who carried out a sequence of experiments.
- He could demonstrate that what animals were doing to the air was being reversed by plants.
- That is, according to him, if animals were making the air impure, plants were making it pure.
- Ingenhouz tried to repeat Priestley’s experiments under different conditions and found that only the green parts of plants when exposed to sunlight could do that.
- Several scientists started working on what green plants were doing with water and air and sunlight and till date we know that-
- Green parts of plants use carbon dioxide in the presence of sunlight (as well as other sources of light) along with water to make glucose, starch and other food materials.
- This process of making food materials is called photosynthesis and such plants are called Autotrophs.
Do you agree with Von Helmont? If nutrients absorbed by plants from soil is equal to the mass of plant/tree what will happen? Think and write your hypothesis.
- We agree with Von Helmont.
- If nutrients absorbed by plants from soil is equal to the mass of the plant by now all the nutrients in the soil might have exhausted.
- Plants are oxygen factories providing enough oxygen in the atmosphere for living organism to survive.
- Plants prepare their own food and for others by the process of photosynthesis making use of sunlights.
Why are some plants called insectivorous plants? Give reasons.
- Some plants not only manufacture their own food but also obtain a part of their nutrition from insects.
- Leaves of these plants are specially modified to trap insects.
- These plants grow in areas deficient in nitrogen.
- Hence they meet their nitrogen requirements from insects.
- So they are called insectivorous plants.
Designery leaves – select any broad-leaved potted plant. Cut a cardboard with a design of your choice and seal the selected leaf with the card board. Let the plant stand under the sun for a week then remove the card board you will get designery leaves plant. Try to make more leaves with designs and display your plant but don’t forget to present your writeup.
The student can do this.
Collect a leaf. Take peels from both sides of the leaf and observe stomata size, shape and number under microscope with the help of your class teacher and write your findings.
Either surfaces of the leaf is surrounded by thin layer of epidermis which shows small tiny pores called as stomata. More number of stomata observed on ventral surface and little number of stomata observed on dorsal surface.
The shape is similar but the coloration is thick towards dorsal and thin towards ventral surface. It means more number of chloroplasts present at dorsal and little number towards ventral. Size of stomata is same and no differentiation.
Prathima said “Mushrooms also a plant” is she correct? How would you support
- Prathima is correct. ‘Mushroom is a plant’.
- Mushrooms grow on rotting wood during the rainy season.
- Mushrooms are not like green plants as they lack chlorophyll.
- They can not make food by photosynthesis. They are saprotrophs.
Photosynthesis is the way plants make food in every leaf by using different items. Write your feelings on this.
- Plants make use of Carbon dioxide and water in the presence of sunlight and chlorophyll to prepare their food and release oxygen.
- Really it is a great thing. The plants are otherwise called oxygen factories.
- We owe a lot to the plant kingdom for many reasons.
a) They provide us food and shelter.
b) They produce oxygen which is very important for all of us.