NCERT Exemplar for Class 7 Science Solutions Chapter 10 Respiration in Organisms

Multiple Choice Questions 

1. Sometimes when we do heavy exercise, anaerobic respiration takes place in our muscle cells. What is produced during this process? 

a) alcohol and lactic acid 

b) alcohol and \[CO_{2}\] 

c) lactic acid and \[CO_{2}\] 

d) lactic acid only 

Ans: A correct answer is an option (d). 

When we perform vigorous activities such as cycling, swimming, running then at that moment glucose from the body is utilized and turned into lactic acid which then causes the fatigue of muscles. 

2. Yeast is used in wine and beer industries because it respires 

a) Aerobically producing oxygen. 

b) Aerobically producing alcohol. 

c) An aerobically producing alcohol. 

d) An aerobically producing \[CO_{2}\]. 

Ans: A correct answer is an option (c). Yeast is a single-celled organism. 

3. During the process of exhalation, the ribs move 

a) Down and inwards. 

b) Up and inwards. 

c) Down and outwards. 

d) Up and outward. 

Ans: A correct answer is an option (a), down and inwards. Carbon dioxide from the body is removed by the process of exhalation. 

4. Breathing is a process that 

i) Provides \[O_{2}\] to the body. 

ii) Breaks down food to release energy. 

iii) Helps the body to get rid of\[CO_{2}\]. 

iv) Produces water in the cells. 

Which of the following gives the correct combination of functions of breathing? 

a) and (ii) 

b) and (iii) 

c) (i) and (iii) 

d) (ii) and (iv) 

Ans: A correct answer is an option (c). 

5. Fish breathe with the help of gills which are richly supplied with blood vessels. The gills help the fish to 

a) Take in oxygen from the air. 

b) Take in oxygen dissolved in water. 

c) Absorb nutrients present in water. 

d) Release waste substances in water. 

Ans: The correct answer is option (b), Take in oxygen dissolved in water. 

6. Earthworms and frogs breathe through their skin because of which the skin of both the organisms is 

a) Moist and rough. 

b) Dry and rough. 

c) Dry and slimy. 

d) Moist and slimy. 

Ans: A correct answer is an option (d), Moist and slimy. 

Very Short Answer Questions 

7. Mark the following statements as True or False. Correct the false statements. 

a) Oxygen breaks down glucose outside the cells of organisms. 

Ans: a) The given statement is false. Oxygen breaks down glucose inside the cells of organisms.

b) Frogs can breathe through their skin as well as lungs. 

Ans: b) The given statement is true. 

c) Insects have spiracles on the lower surface of the body. 

Ans: c) The given statement is false. Insects have spiracles on the sides of the body. 

d) Exhaled air has more percentage of \[CO_{2}\] than inhaled air. 

Ans: d) The given statement is true. 

8. Fill in the blanks with suitable words. 

a) The roots of a plant take up oxygen from the ______ trapped between the ________ particles. 

Ans: a) The roots of a plant take up oxygen from the air trapped between the soil particles. 

b) Diaphragm forms the ___________ of the chest cavity. 

Ans: b) Diaphragm forms the Floor of the chest cavity. 

c) Exchange of gases in the leaves take place with the help of __________. 

Ans: c) Exchange of gases in the leaves takes place with the help of Stomata.

d) Cockroaches breathe with the help of air tubes called ___________. 

Ans: d) Cockroaches breathe with the help of air tubes called Tracheae

Short Answer Questions 

9. Pick the odd-one-out from each of the groups given below on the basis of respiratory organs. Give a reason for your answer. 

a) cockroach, grasshopper, snail, ant 

Ans: An ant, grasshopper, and cockroach are insects. They respire through the trachea. Snail has different respiration organs. So, the odd one is a snail. 

b) lizard, cow, earthworm, snake 

Ans: Snake, cow, and lizard respire through lungs. Earthworms respire through the skin (moist). So, the odd one is the earthworm. 

c) crocodile, whale, dolphin, fish 

Ans: Dolphin, Whale and Crocodile have their respiratory organs. Fishes respire through their gills. So, the odd one is fish. 

d) snake, tadpole, crow, goat.

Ans: Goat, crow, and snake have lungs but tadpoles do not. So, the odd one is a tadpole. 

10. Which gas present in the air is essential for aerobic respiration? What is the role of oxygen during respiration? 

Ans: Oxygen is responsible for aerobic respiration. This gas helps in oxidizing the food and then breaking down it into smaller molecules. In this way, the energy is created and then supplied to various organs so that they can function. 

11. On average, an adult human being at rest breathes 15–18 times per minute. The breathing rate, however, may differ under different conditions. Arrange the following activities given in the box in order of increasing breathing rates and give a reason for your answer. Sleeping, cycling, brisk walk, watching T.V. 

Ans: Sleeping > Watching > T.V. > Brisk Walk > Cycling. The breathing rate becomes faster when we are working. The more strenuous work, the more is the breathing rate, and so, that sufficient oxygen can reach the cells. 

12. On a very cold morning, Boojho and Paheli were talking with each other as they walked down to their school. They observed that the air coming out of their mouth looked like smoke. They were amused and wondered how it happened. Help them find the answer. 

Ans: On a cold day, the air coming out of our mouth gets condensed into the mist because of the cold air of the atmosphere. 

13. Whenever we feel drowsy or sleepy, we start yawning. Does yawning help us in any way?

Ans: Yawning helps us to take more oxygen at that moment and this way more oxygen is supplied to the organs and this helps us to stay awake. 

14. Insects and leaves of a plant have pores through which they exchange gases with the atmosphere. Can you write two points of difference between these pores with respect to their position, number, and extension into the body? 

Ans: Spiracles are the small pores that are present in insects. These pores help the exchange of gases insects and they respire through this. In plants, stomata are present. These stomata are small minute apertures that help in the exchange of gases in plants. 

Long Answer Questions 

15. Paheli participated in a 400 m race competition held at her school and won the race. When she came home, she had mixed feelings of joy and pain as she had cramps in her leg muscles. After a massage, she was relieved of the pain. Answer the following questions related to the situation. 

(i) What can be the possible reasons for the pain in her legs? 

Ans: During heavy physical movement muscle cells are exhaled anaerobically producing lactic acid. Accumulation of lactic acid may increase pain. 

(ii)Why did she feel comfortable after a massage? 

Ans: The hot water bath and massage bath give relief from muscle cramps or pain. It improves the circulation of blood leading to an increased supply of oxygen to the muscle cells. It also helps in a complete breakdown of lactic acid into carbon dioxide and water. 

16. Observe Figure 10.1 carefully and answer the following 

(a) In which jar, will the amount of \[CO_{2}\] be the highest and why? 

Ans: Jar C will be the highest amount of \[CO_{2}\]. There are mice in jar C. They breathe out carbon dioxide. So, \[CO_{2}\] will increase.

(b) In which jar, will the amount of \[CO_{2}\] be the lowest and why?

Ans: Jar A will be the lowest amount of \[CO_{2}\]. In Jar A there is a plant. So, because of the process of photosynthesis \[CO_{2}\] will decrease continuously. 

17. Observe Figure 10.2 carefully and answer the following questions.

(a) Which process is being tested in the activity? 

Ans: The tested experiment is an exhalation procedure during respiration.

(b) What is the result of the activity? Give reasons. 

Ans: In test tube B, lime water will change into milky but the color of test tube A will not change. The reason behind this is “carbon dioxide”. \[CO_{2}\] will be present in the exhaled air and mix with lime water. So, lime water will change its colour. 

18. A food stall owner was preparing dough for making bhaturas. He added a pinch of yeast and sugar to the dough and left it in a warm place. After a few hours, the dough had risen. There was a sour smell too. a) Why did the dough rise? b) Why did the dough smell sour? c) Why was sugar added to the dough? d) What would have happened if the dough was kept in the refrigerator, soon after it was prepared? 

Ans: a) During respiration yeast produces \[CO_{2}\]. This makes the dough rise. b) Yeast produces alcohol during anaerobic respiration. Because of this, it smells like dough. c) Sugar added to the dough acts as food for yeast. d) If the dough was kept in the refrigerator, yeast will not respire. Also, the dough will not rise and it will not produce any type of sour smell. 

19. Observe the figures given as Figure 10.3 (A) and (B) and answer the following. 

a) Which of the figures A or B indicates the process of inhalation and which the process of exhalation? 

Ans: Fig. (a) indicates the process of inhalation, and Fig (b) indicates the process of exhalation. 

b) In the figure label the arrows and indicate the direction of 

i) movement of air 

ii)movement of the diaphragm 

iii) movement of ribs 

Ans: The labelled figure is: 

20. Match the names of organisms in Column I with their organs of breathing given in Column II.

Ans: The answers the column I are written against column II

What is NCERT Exemplar for Chapter 10 Respiration in Organisms?

NCERT is an autonomous, government-instituted body that was created in 1961 by merging seven older bodies. The point of the NCERT was to have one body take care of all of the educational requirements of the central boards. This included the creation of the syllabus, textbooks, workbooks, and exam patterns. 

The NCERT Exemplar Science workbook is one series of workbooks from the NCERT Exemplar series. These books aren't traditional textbooks because they only contain questions based on the syllabus covered in the real textbooks. Hence why they're considered workbooks instead. There is a different series for each subject, divided by year. 

Benefits of downloading Class 7 NCERT Exemplar Science Chapter 10 solutions

Vedantu has provided the solutions to the questions in the 10th Chapter of the NCERT Exemplar Science workbook to aid you in your studies. By referring to these solutions, you will be able to understand how to solve the questions in your workbook quickly and efficiently. This will speed up the time it takes you to solve the questions while also allowing you to learn how to logically deduce the answers on your own.