AP State Syllabus AP Board 7th Class Science Solutions Chapter 11 Respiration in Organisms Textbook Questions and Answers.

AP State Syllabus 7th Class Science Solutions 11th Lesson Respiration in Organisms

7th Class Science 11th Lesson Respiration in Organisms Textbook Questions and Answers

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Question 1.
Fill in the blanks and give reasons.
i) ……… are the respiratory organs of fish.
ii) In a cockroach, a network of ……… is found.
iii) ……… are found on leaves for the exchange of gases.
i) Gills
ii) respiratory tubes
iii) Stomata
i) Reason: The gills absorb the oxygen that is dissolved in the water.
ii) Reason: Respiratory tubes help the cockroach to breath.
iii) Reason: Exchange of air in leaves takes place continuously through stomata.

AP Board 7th Class Science Solutions Chapter 11 Respiration in Organisms

Question 2.
Select correct answer and give reasons.
i) The process which involves the exchange of gases is called ( )
a. Respiration
b. Circulation
c. Digestion
d. Breathing
a. Respiration
Reason: Exchange of gases takes place only in respiration by the oxidation of food material.

ii) During inspiration air passes into lungs due to ( )
a. Increased volume of thoracic cavity
b. Fall in pressure inside the lungs
c. Increase in the volume of thoracic cavity and fall in lung pressure
d. Muscular expansion of lungs
c. Increase in the volume of thoracic cavity and fall in lung pressure
Reason: If volume increases, pressure will be decreased. Hence gases occupy the lungs by inspiration.

iii) Roots respire through ( )
a. Spiracles
b. Lenticels
c. Stomata
d. Air spaces
b. Lenticels
Reason: Leaves are surrounded by epidermis with numerous pores called stomata. But, stems and roots covered by bark with lenticels. Hence roots respire through lenticels.

iv) Which of the following animals breathe through their skin and lungs? ( )
a. Fish
b. Frog
c. Snake
d. Earthworm
b. Frog
Reason: Frogs can respire through lungs and skin. In rest both hibernation and aestivation frog lives in burrow of the soil, there it respires through skin and respire by lungs in water as well as on land.

AP Board 7th Class Science Solutions Chapter 11 Respiration in Organisms

v) What happens to lime water, when we exhale air into it? ( )
a. Remains same
b. Turns blue
c. Turns milky
d. Becomes colourless
c. Turns milky
Reason: Lime water turns into milky by the action of carbon dioxide. Exhale air consists more carbon dioxide.

vi) Plants respire through ( )
a. Cells
b. Stomata
c. Gills
d. Gill membrane
b. Stomata
Reason: Plants only having minute pores called stomata help in exchange of gases.

vii) The respiratory organs in cockroach are ( )
a. Lungs
b. Gills
c. Lenticels
d. Spiracles
d. Spiracles
Reason: Cockroach is surrounded by hard coat and it has small openings to outside on either side of the body called spiracles. Spiracles exchange the gases in cockroach.

Question 3.
What is respiration? How is it different from breathing?

  1. It is oxidation of food to form carbon dioxide, water vapour and energy.
  2. It is a biological process.
  3. Energy is released in the form of ATP.
  4. Enzymes are involved in this process.


  1. It is simply an intake of fresh air and removal of foul air.
  2. It is a physical process.
  3. No energy is released rather used.
  4. No Enzymes are involved in the process.

AP Board 7th Class Science Solutions Chapter 11 Respiration in Organisms

Question 4.
Frogs breathe through their skin as well as their lungs. Explain.

  1. Frog breathes, with its Lungs when it is on land.
  2. When it goes deep under ground and sleeps twice every year, its moist skin takes over the function of its lungs.

Question 5.
If you want to know about ‘Actions of gases in lungs’. What questions you would like to ask?
The following questions I would like to ask.

  1. What will happen to the gases in the Lungs?
  2. How are the gases transferred to different parts of the body?
  3. In return what comes to the lungs?
  4. How are the gases return to the Lungs?

Question 6.
If you did this experiment of respiration with fruits and dry leaves, what would the result be? Explain.

  1. In dry leaves respiration do not take place.
  2. In fruits also this biochemical process “ceases.

Question 7.
It is very interesting to watch fishes in an aquarium. Make your own bottle aquarium.
The student can do it.

Question 8.
Do you find any relation between plants and animals by their respiration and photosynthesis?

  1. Respiration is observed both in plants and animals.
  2. Photosynthesis is the process we observe in plants. By this process, plants prepare their own food.
  3. Animals cannot produce their own food. They depend on plants and other animals.
  4. Oxygen is given out in photosynthesis and photosynthesis occurs in the day time.
  5. Oxygen is taken in in respiration and energy is released.

AP Board 7th Class Science Solutions Chapter 11 Respiration in Organisms

Question 9.
As if wondered how plants and animals which live underwater also respire. Do you know how?

  1. Some plants can survive underwater taking the oxygen dissolved in water.
  2. Some animals living underwater have special respiratory organs to take in the dissolved oxygen in water.
  3. Thus plants and animals which live underwater can survive.

Question 10.
Imagine the lungs and size of an elephant. Is there any relation between body size and lung size? Collect information from School Library or Internet.
The elephant is the only mammal whose pleural space is absent. The lungs are more elastic and are connected by connecting tissues to the thorax and diaphragm. Its wide capacity of air filling is 310 litres for one to breathe. The size of the lungs is always proportionate to the size of the body of all terrestrial animals whose respiration is pulmonary. The elasticity of the elephant lungs is more convenient to the movement of the body. The absence of pleural space helps in adjustment and applying negative force on lungs when the trunk raises up to the maximum height.