NCERT Exemplar solutions for Science [English] Class 7 chapter 10 - Respiration in Organisms [Latest edition]

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

Yeast is used in wine and beer industries because it respires

During the process of exhalation, the ribs move

Breathing is a process that

1. provides O₂ to the body.
2. breaks down food to release energy.
3. helps the body to get rid of CO₂.
4. produces water in the cells.

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

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

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

Mark the following statement as True or False. Correct the false statement.

Oxygen breaks down glucose outside the cells of organisms.

Mark the following statement as True or False. Correct the false statement.

Frogs can breathe through their skin as well as lungs.

Mark the following statement as True or False. Correct the false statement.

Insects have spiracles on the lower surface of the body.

Mark the following statement as True or False. Correct the false statement.

Exhaled air has more percentage of CO2 than inhaled air

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

Diaphragm forms the ___________ of the chest cavity.

The exchange of gases in the leaves takes place with the help of __________.

Cockroaches breathe with the help of air tubes called ___________.

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

cockroach, grasshopper, snail, ant

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

lizard, cow, earthworm, snake

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

crocodile, whale, dolphin, fish

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

snake, tadpole, crow, goat

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

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 walking, watching T.V

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.

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

Insects and 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?

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.

1. What can be the possible reasons for the pain in her legs?
2. Why did she feel comfortable after a massage?

Observe Figure 10.1 carefully and answer the following questions.

1. In which jar, will the amount of CO₂ be the highest and why?
2. In which jar, will the amount of CO₂ be the lowest and why?

Observe Figure 10.2 carefully and answer the following questions.

1. Which process is being tested in the activity?
2. What is the result of the activity? Give reasons.

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.

Why did the dough rise?

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.

Why did the dough smell sour?

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.

Why was sugar added to the dough?

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.

What would have happened if the dough was kept in the refrigerator, soon after it was prepared?

Observe the figures given in Figures 10.3 (A) and (B) and answer the following.

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

Observe the figures given in Figures 10.3 (A) and (B) and answer the following.

In the figure label the arrows and indicate the direction of

1. movement of air
2. movement of the diaphragm
3. movement of ribs

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