NCERT Class VII Science Solutions: Chapter 10-Respiration in Organisms Part 2

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Question 4:

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

Answer:

Living organisms release during respiration whereas plant utilize for photosynthesis. So, the test tube A will have the highest concentration of carbon dioxide because the carbon dioxide as it comes only by respiration of snail. In test tubes B and C, a part of the carbon dioxide is utilized by the plant for photosynthesis and hence there is less concentration of carbon dioxide.

As showing in images is a highest concentration of CO 2

Highest Concentration of CO 2

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Question 5:

Tick the correct answer:

  1. In cockroaches, air enters the body through

  2. Lungs

  3. Gills

  4. Spiracles

  5. Skin

  6. During heavy exercise, we get cramps in the legs due to the accumulation of

  7. Carbon dioxide

  8. Lactic acid

  9. Alcohol

  10. Water

  11. Normal range of breathing rate per minute in an average adult person at rest is:

  12. 9 – 12

  13. 15–18

  14. 21–24

  15. 30–33

  16. During exhalation, the ribs

  17. Move outwards

  18. Move downwards

  19. Move upwards

  20. Do not move at all

Answer:

  1. In cockroaches, air enters the body through (c) spiracles.

Diagram shows air enters the body through spiracles in cockr …

Air Enters the Body through Spiracles

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  1. During heavy exercise, we get cramps in the legs due to the accumulation of (b) lactic acid.

As showing in images is a result for lactic acid

Result for Lactic Acid

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  1. Normal range of breathing rate per minute in an average adult person at rest is (b) 15–18.

  2. During exhalation, the ribs (b) move downwards.

This diagram shows the ribs move back and downwards

The Ribs Move Back and Downwards

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