Respiration in Organisms Practice Questions

Class 7 · Science · 1213 free MCQs with instant results and detailed explanations.

1213

Total

362

Easy

597

Medium

254

Hard

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Topics in Respiration in Organisms

Breathing in Animals 405

Breathing 402

Cellular Respiration 406

Sample Questions from Respiration in Organisms

Here are 10 sample questions. Start a quiz to get randomized questions with scoring.

Easy

What is the primary function of the respiratory system in humans?

A. To transport nutrients

B. To exchange gases

C. To digest food

D. To circulate blood

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Correct Answer: B

The primary function of the respiratory system is to exchange oxygen and carbon dioxide between the body and the environment.

Easy

Which organ is primarily responsible for gas exchange in humans?

A. Heart

B. Lungs

C. Liver

D. Kidneys

Show Answer & Explanation

Correct Answer: B

The lungs are the primary organs where oxygen is absorbed and carbon dioxide is released during breathing.

Easy

What process do plants use to take in carbon dioxide?

A. Photosynthesis

B. Respiration

C. Transpiration

D. Fermentation

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Correct Answer: A

Plants take in carbon dioxide during photosynthesis to produce energy and oxygen.

Medium

Which of the following organisms uses lungs for respiration?

A. Fish

B. Bird

C. Earthworm

D. Turtle

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Correct Answer: B

Birds have developed lungs that allow them to efficiently exchange gases while flying.

Medium

What is the main purpose of respiration in living organisms?

A. To produce light

B. To release energy

C. To absorb nutrients

D. To create sound

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Correct Answer: B

Respiration primarily serves to release energy from food substances for cellular activities.

Medium

In humans, which part of the respiratory system is responsible for gas exchange?

A. Trachea

B. Bronchi

C. Alveoli

D. Pharynx

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Correct Answer: C

Alveoli are tiny air sacs in the lungs where the exchange of oxygen and carbon dioxide occurs.

Medium

Which of the following gases is primarily inhaled during respiration?

A. Carbon Dioxide

B. Oxygen

C. Nitrogen

D. Hydrogen

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Correct Answer: B

Oxygen is the main gas required for cellular respiration and is inhaled by organisms.

Hard

Which of the following statements correctly describes the process of breathing in humans?

A. Breathing is the process of gas exchange that occurs in the alveoli.

B. Breathing only involves the diaphragm and does not include rib movement.

C. Breathing is the same as cellular respiration.

D. Breathing occurs only when we are at rest.

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Correct Answer: A

Breathing involves inhaling oxygen and exhaling carbon dioxide, primarily occurring in the alveoli, which are tiny air sacs in the lungs.

Hard

In which part of the respiratory system does the exchange of gases primarily take place?

A. Bronchi

B. Trachea

C. Alveoli

D. Pharynx

Show Answer & Explanation

Correct Answer: C

Gas exchange occurs in the alveoli, where oxygen enters the blood and carbon dioxide is removed.

Q10

Hard

Why do fish use gills for breathing instead of lungs?

A. Gills are more efficient in extracting oxygen from water.

B. Fish do not need oxygen.

C. Lungs cannot function in water.

D. Fish have too much carbon dioxide to use lungs.

Show Answer & Explanation

Correct Answer: A

Gills allow fish to efficiently extract dissolved oxygen from water, which is essential for their survival, unlike lungs that work better in air.

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Respiration in Organisms — Class 7 Science Practice Questions Online

This page contains 1213 practice MCQs for the chapter Respiration in Organisms in Class 7 Science. The questions are organized by difficulty — 362 easy, 597 medium, 254 hard — so you can choose the right level for your preparation.

Every question includes a detailed explanation to help you understand the concept, not just memorize answers. Take a timed quiz to simulate exam conditions, or practice at your own pace with no time limit. This chapter covers 3 topics, giving you comprehensive coverage of the entire chapter.