Important Questions Class 7 Science Chapter 10

Important Questions Class 7 Science Chapter 10 – Respiration in Organisms

Science is a complex subject with a wide range of topics. Each concept requires a unique approach. Learning and understanding more about a specific topic in an orderly manner would help in gaining expertise in this subject. To be a good performer in Science, students need to have a strong hold on the basic concepts required to grasp further complex topics that will be introduced in higher classes.

Chapter 10 of Class 7 Science is about ‘Respiration in Organisms’. In this chapter, students will learn about various topics that will around understanding respiration, different types of respiration, and the respiration process in plants, animals, and humans. 

Extramarks is a trusted online learning platform which is used by lakhs of students from Class 1 to Class 12. Our expert Science teachers have developed comprehensive study materials such as NCERT solutions, chapter notes, CBSE revision notes, and so on.

For providing practice materials for our students, our teachers have collated questions from various sources including the NCERT textbook, NCERT exemplar book, CBSE past years’ question papers, CBSE sample papers, and other reference books. Students can refer to our Important Questions Class 7 Science Chapter 10 to get access to all these questions which will help them to revise the full chapter while solving the questions. 

By practising from Class 7 Science Chapter 10 Important Questions, students will be able to have strong foundational knowledge with all the important fundamental topics to cover for excelling in the CBSE exams.

Important Questions Class 7 Science Chapter 10 – With Solutions

For the overall preparation of students for exams, we suggest students  refer to our Important Questions Class 7 Science Chapter 10. This question bank includes questions from various sources and comprises step-by-step solutions that are guaranteed to improve the students’ performance and their grades.

It is advised that students solve these questions to understand their preparedness for the exams.  

Below is a list of a few questions and answers taken from our question bank of Important Questions Class 7 Science Chapter 10:

Question 1: List the similarities and differences between aerobic and anaerobic respiration.

Answer 1:

 Similarities between aerobic and anaerobic respiration are: 

1. In both respirations, the food particles are broken down into smaller, digestible pieces to release energy.
2. Both aerobic and anaerobic respiration occur inside the cell.
3. Both respiration processes produce byproducts.

Differences between aerobic and anaerobic respiration are:

Question 2: Take three test tubes. Fill ¾th of each with water. Label them A, B and C. Keep a snail in test tube A, a water plant in test tubes B and C, and keep the snail and plant both. Which test tube would have the highest concentration of CO2?

Answer 2: We are now aware that plants photosynthesis in the presence of CO2 to produce glucose and by-product oxygen. Therefore, test tube B and test tube C contain plants that will have no concentration of CO2 as plants use up the CO2, present. In test tube A, where a snail is placed, there will be a high concentration of CO2 due to aerobic respiration taking place.

Question 3: Tick the correct answer:

(a) In cockroaches, air enters the body through:

(i) lungs (ii) gills (iii) spiracles (iv) skin.

(b) During heavy exercise, we get cramps in the legs due to the accumulation of:

(i) carbon dioxide (ii) lactic acid (iii) alcohol (iv) water.

(c) Normal range of breathing rate per minute in an average adult person at rest is:

(i) 9–12 (ii) 15–18 (iii) 21–24 (iv) 30–33.

(d) During exhalation, the ribs:

(i) move outwards (ii) move downwards (iii) move upwards (iv) do not move at all.

Answer 3 :

1. (iii) spiracles
2. (ii)lactic acid
3. (ii)15-18
4. (ii)move downwards

Question 4: Why does an athlete breathe faster and deeper than usual after finishing the race?

Answer 4: Athletes require a lot of oxygen during the race to form and release energy; thus, the athlete breathes faster and deeper than usual after the race to release energy; additionally, if the oxygen does not reach the cell, there is a chance of cramping after the race due to the formation of lactic acid.

Question 5: Why do we often sneeze when we inhale a lot of dust-laden air?

Answer 5:  When we inhale a lot of dust-laden air, the nasal cells get irritated as a reflex response; therefore, dust is thrown out through sneezing.

Question 6: 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 CO2

(c) lactic acid and CO2

(d) lactic acid only

Answer 6 : (d) lactic acid only

During exercise, the body uses oxygen for aerobic respiration at a higher rate; since oxygen is at a limited amount, the body shifts to anaerobic respiration, which gives lactic acid as a by-product.

Question 7: During the process of exhalation, the ribs move

(a) down and inwards.

(b) up and inwards.

(c) down and outwards.

(d) up and outward.

Answer 7: (a) Down and inwards

During exhalation, the diaphragm moves up, and the ribs move downwards and inwards, decreasing the 

Space in the chest cavity increases the air pressure inside the lungs, which forces the air out of the lungs.

Question 8: Breathing is a process that

(i) provides O2 to the body.

(ii) breaks down food to release energy.

(iii) helps the body to get rid of CO2.

(iv) produces water in the cells.

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

(a) (i) and (ii)

(b) (ii) and (iii)

(c) (i) and (iii)

(d) (ii) and (iv)

Answer 8 : (c) (i) and (iii)

Breathing is a process that requires the intake of oxygen-rich air and the exhalation of carbon dioxide air, which is expelled from the body with the help of respiratory organs.

Question 9: Which gas present in the air is essential for aerobic respiration? What is the role of oxygen during respiration?

Answer 9: Atmospheric oxygen is essential for aerobic respiration and to help break down food to release energy.

Question 10: Whenever we feel drowsy or sleepy, we start yawning. Does yawning help us in any way?

Answer 10:  Whenever we feel drowsy or sleepy, we start yawning, and our respiration rate slows down. As our lungs do not get enough oxygen, we yawn, bringing an extra supply of oxygen-rich air to the lungs and delivering it to the brain, helping us to stay awake.

Question 11: 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?

Answer 11: 

1. Yeast is present in the dough during respiration to produce CO2, which makes the dough rise.
2. Yeast undergoing anaerobic respiration produces alcohol, which gives a sour smell to the dough.
3.  Sugar acts as a food source for the yeast present in the dough.
4. If the dough is kept in the refrigerator, then the yeast will not multiply, hence not releasing alcohol and co2, making the dough rise and have a sour smell.

Question 12:Paheli participated in a 400 m race competition 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. She was relieved of the pain after a massage. Answer the following questions related to the situation.

(a) What could be the possible reasons for the pain in her legs?

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

Answer 12 : 

1. Pain in her legs is caused by an accumulation of lactic acid in her muscles, formed due to anaerobic respiration during her intense physical exercise.
2. She felt comfortable after the massage as the massage improves blood circulation, thereby increasing the blood flow and eliminating the lactic acid, breaking it down into CO2 and water. 

Question 13: Insects and the leaves of a plant have pores through which they exchange gases with the atmosphere. Can you write two points of differences between these pores with respect to their position, number and extension into the body?

Answer 13:  Two points of difference between these pores with respect to their position, number, and extension into the body are:

1. The spiracles in insects can be found on the sides of the insect’s body, while the stomata in plants are present on the lower surface of the leaves in plants.
2. Insects’ spiracles are lesser in number as compared to stomata in plants.
3. Spiracles are a part of an extensive network of a tracheal system which is absent in the leaves.

Question 14: Explain the process of breathing.

Answer 14: The air inhaled is transported to every part of the body and ultimately is transported to every cell in the body. The oxygen in the air helps in the breakdown of food in the cells to release energy. This process is called cellular respiration. 

Question 15: Define cellular respiration.

Answer 15: The oxygen in the air we inhale is transported to every part of the body and every cell through capillaries.  Oxygen is needed in the breakdown of food. This process of breakdown of food in the cell for the release of energy is called cellular respiration. Cellular respiration occurs in the cells of every organism.

Question 16: Define respiration in plants.

Answer 16: Plants take in oxygen from the air and give out carbon dioxide through tiny pores called stomata, situated in the back of the leaves. Oxygen is used to break down glucose into carbon dioxide and water inside the cell.

Question 17: What is the total percentage of oxygen and carbon dioxide in the inhaled air and exhaled air?

Answer 17: The percentage of oxygen in inhaled air is 21% and carbon dioxide is 0.04%, respectively, and the percentage of oxygen in exhaled air is 16.4% and carbon dioxide is 4.4%, respectively.

Question 18: Explain respiration in 

1) Cockroach

2) Earthworm

Answer 18: 

1. Cockroach: Cockroaches have a small opening on the side of their bodies known as spiracles. Through spiracles, oxygen-rich air rushes through the tracheal tube and diffuses into the body tissue to reach every cell in the body. In the same way, carbon dioxide-rich blood from a cell enters tracheal tubes and exits the body through spiracles through the process of diffusion.
2. Earthworm: The earthworm breathes through the skin. The skin of earthworms is moist and slimy.  Oxygen enters the body of the earthworm through diffusion and exits in a similar way.

Question 19: Explain respiration in aquatic animals.

Answer 19: Aquatic animals have special projections of the skin (organs ) called gills that help them use oxygen dissolved in water. Gills are rich in blood vessels to help in the diffusion of gases.

Benefits of Solving Important Questions Class 7 Science Chapter 10

The topics covered in Science Chapter 10 Class 7 Important Questions will be the foundation for the concepts that will be covered in the chapters of Class 11. Therefore, it is advised for students to practise Important Questions Class 7 Science Chapter 10 to ensure a strong conceptual understanding of all the concepts covered in Class 7 Science. 

A few of the benefits of solving questions from our list of Important Questions Class 7 Chapter 10 are listed below:

• The question bank contains questions from the NCERT textbook, NCERT exemplar, past years’ question papers, and various other reference books.  While going through these questions, students will get to access their knowledge about different topics in the chapter. While solving these questions, students will be able to revise the whole chapter, covering the entire syllabus. 
• Important Questions Class 7 Chapter 10 is a set of questions created by subject experts solely for the purpose of assisting students in their exam preparation. There is a good possibility of these questions appearing in exams. It makes it easier for the students to answer problems by practising these questions in advance.
• Chapter 10 Class 7 Science Important Questions contains questions in various formats through which students can get access to various materials required for exam preparation based on their needs. They can work on understanding concepts in terms of a broader spectrum of topics by searching across the Extramarks website after registration.
• Important Questions Class 7 Science Chapter 10 includes MCQs, short answer type questions, long answer type questions and reasoning type questions which enables students with a wider variety of ways to strengthen their preparation during exams.

Extramarks provides comprehensive learning solutions for students from Class 1 to Class 12. We have abundant resources available on our website, along with essential questions and answers. Students can click on the links given below to access some of these resources:

• NCERT books
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• Important Formula from Mathematics and Science
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