Questions and Answers on Respiration in Organisms
1. Why does an athlete breathe faster and deeper than usual after finishing a race?
Answer: An athlete breathes faster and deeper to supply more oxygen to the muscles and remove the extra carbon dioxide produced during exercise.
2. List the similarities and differences between aerobic and anaerobic respiration.
Answer:
- Similarities:
- Both processes release energy.
- Both involve the breakdown of glucose.
- Differences:
- Aerobic respiration requires oxygen; anaerobic respiration does not.
- Aerobic respiration produces more energy; anaerobic respiration produces less.
- By-products of aerobic respiration are carbon dioxide and water; anaerobic respiration produces substances like lactic acid or alcohol.
3. Why do we often sneeze when we inhale a lot of dust-laden air?
Answer: Sneezing helps expel unwanted particles like dust and pollen that irritate the nasal cavity, ensuring clean air enters the respiratory system.
4. In the experiment with test tubes A, B, and C, which will have the highest concentration of CO2?
Answer: Test tube A (with the snail only) will have the highest concentration of CO2 because the snail respires and releases CO2, while no plants are present to absorb it.
5. Tick the correct answers:
(a) In cockroaches, air enters the body through:
(iii) Spiracles
(b) During heavy exercise, we get cramps due to the accumulation of:
(ii) Lactic acid
(c) Normal breathing rate in an average adult person at rest is:
(iv) 15–18
(d) During exhalation, the ribs:
(iii) Move downwards
6. Match the items in Column I with Column II:
| Column I | Column II |
|---|---|
| (a) Yeast | (iii) Alcohol |
| (b) Diaphragm | (iv) Chest cavity |
| (c) Skin | (i) Earthworm |
| (d) Leaves | (v) Stomata |
| (e) Fish | (ii) Gills |
| (f) Frog | (vi) Lungs and skin |
7. Mark ‘T’ or ‘F’ for the following statements:
(i) During heavy exercise, the breathing rate of a person slows down. (F)
(ii) Plants carry out photosynthesis only during the day and respiration only at night. (F)
(iii) Frogs breathe through their skins as well as their lungs. (T)
(iv) The fishes have lungs for respiration. (F)
(v) The size of the chest cavity increases during inhalation. (T)
8. Find the hidden words in the square related to the respiratory system:
(i) Spiracles
(ii) Ribs
(iii) Diaphragm
(iv) Stomata
(v) Openings on the sides of insects
(vi) Lungs
(vii) Nostrils
(viii) Yeast
(ix) Cockroach
9. Why do mountaineers carry oxygen with them?
Answer: (b) The amount of air available to a person is less than that available on the ground.
Extended Learning Activities and Projects
1. Explain respiration in fish using observations of gill movements.
Answer: Fish take in water through their mouths, which passes over the gills. The gills extract oxygen dissolved in water and release carbon dioxide. The gill covers move alternately to facilitate this process.
2. Investigate the harmful effects of smoking.
Answer: Smoking damages lungs, causes diseases like cancer and chronic respiratory issues, and leads to reduced oxygen-carrying capacity of blood. Collect statistics on smokers in your area and create awareness.
3. Learn about artificial respiration from a doctor:
- When is it needed? During emergencies like drowning or breathing failure.
- Temporary or permanent? It can be both, depending on the condition.
- Oxygen source? Hospitals or portable oxygen cylinders.
4. Investigate the breathing rate among family and friends:
- Is the breathing rate different for children and adults? Yes, children breathe faster.
- Is there a difference between males and females? Yes, males generally have slightly slower rates.
- Reasons: Children’s higher metabolic rates and differences in lung capacity.
1. What is respiration?
Answer: Respiration is a process where food is broken down to release energy in the presence or absence of oxygen.
2. What is cellular respiration?
Answer: Cellular respiration is the breakdown of glucose in cells to release energy.
3. What is aerobic respiration?
Answer: Aerobic respiration is the breakdown of food using oxygen, producing carbon dioxide, water, and energy.
4. What is anaerobic respiration?
Answer: Anaerobic respiration is the breakdown of food without oxygen, producing less energy along with substances like alcohol or lactic acid.
5. Give an example of an organism that respires anaerobically.
Answer: Yeast respires anaerobically to produce alcohol and carbon dioxide.
6. Why do muscles sometimes respire anaerobically?
Answer: During heavy exercise, oxygen supply is insufficient, so muscles respire anaerobically, producing lactic acid and energy.
7. What causes muscle cramps?
Answer: Muscle cramps are caused by the accumulation of lactic acid due to anaerobic respiration in muscles.
8. How can muscle cramps be relieved?
Answer: Muscle cramps can be relieved by improving blood circulation through a hot water bath or massage, which helps supply oxygen to break down lactic acid.
9. What is breathing?
Answer: Breathing is the process of inhaling oxygen-rich air and exhaling carbon dioxide-rich air.
10. What is the breathing rate?
Answer: The breathing rate is the number of breaths (inhalation and exhalation) taken per minute.
11. What happens to the breathing rate during exercise?
Answer: During exercise, the breathing rate increases to supply more oxygen to the body.
12. What is the average breathing rate of an adult at rest?
Answer: The average breathing rate of an adult at rest is 15–18 breaths per minute.
13. What is inhalation?
Answer: Inhalation is the process of taking in air rich in oxygen.
14. What is exhalation?
Answer: Exhalation is the process of giving out air rich in carbon dioxide.
15. What role does the diaphragm play in breathing?
Answer: The diaphragm moves down during inhalation to increase chest cavity space and up during exhalation to push air out of the lungs.
16. What are lungs?
Answer: Lungs are respiratory organs where the exchange of oxygen and carbon dioxide occurs.
17. Why do we sneeze?
Answer: Sneezing helps expel unwanted particles like dust and pollen from the nasal cavity.
18. What are spiracles?
Answer: Spiracles are small openings on the sides of the bodies of insects that allow air to enter their tracheal system.
19. How do earthworms breathe?
Answer: Earthworms breathe through their moist and slimy skin, which allows gases to pass through.
20. How do fish breathe underwater?
Answer: Fish use gills to extract oxygen dissolved in water.
21. What happens when carbon dioxide is passed through lime water?
Answer: Lime water turns milky due to the formation of calcium carbonate.
22. Why do whales and dolphins surface regularly?
Answer: Whales and dolphins surface to breathe air as they have lungs and cannot extract oxygen from water.
23. How do plants respire?
Answer: Plants respire by taking in oxygen and releasing carbon dioxide through tiny pores called stomata.
24. How do roots of plants take in oxygen?
Answer: Roots take in oxygen from air spaces between soil particles.
25. What is the difference between inhaled and exhaled air?
Answer: Inhaled air has more oxygen (21%) and less carbon dioxide (0.04%), while exhaled air has less oxygen (16.4%) and more carbon dioxide (4.4%).
26. What is the role of the nasal cavity in breathing?
Answer: The nasal cavity filters, moistens, and warms the air before it enters the lungs.
27. Why do we yawn when drowsy?
Answer: Yawning increases oxygen intake when the body feels low on oxygen.
28. How is respiration in humans different from that in insects?
Answer: Humans use lungs for respiration, while insects use spiracles and a tracheal system.
29. What is the role of traditional breathing exercises like pranayama?
Answer: Traditional breathing exercises increase lung capacity and oxygen intake, supplying more energy to the body.
30. What happens if a potted plant is overwatered?
Answer: Overwatering fills air spaces in the soil, depriving roots of oxygen, which can harm the plant.
These questions cover all key concepts about respiration in organisms in a simple and easy-to-understand manner.
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