Chapter 6 Respiration in Organisms Question/Answers with Important Points

Important Words for Respiration in Organisms

Aerobic respiration – The process of producing energy from food using oxygen. (वायवीय श्वसन)
Anaerobic respiration – The process of producing energy from food without using oxygen. (अनावायवीय श्वसन)
Breathing rate – The number of breaths taken per minute. (श्वास दर)
Cellular respiration – The process by which cells produce energy from food. (कोशिकीय श्वसन)
Diaphragm – A muscle that helps in breathing by moving up and down. (मध्यपट)
Exhalation – The process of breathing out air from the lungs. (श्वास छोड़ना)
Gills – Organs that allow fish and some other animals to breathe underwater. (गलफड़े)
Lungs – Organs that allow air-breathing animals to take in oxygen and expel carbon dioxide. (फेफड़े)
Inhalation – The process of breathing in air into the lungs. (श्वास लेना)
Spiracles – Small openings on the surface of some animals that allow air to enter the tracheae. (श्वास छिद्र)
Tracheae – Tubes in the respiratory system of insects that transport air directly to the tissues. (श्वासनली)
Ribs – Bones that protect the chest cavity and support the upper body. (पसलियाँ)

Exercise Question With Answers:👉

1. Why Does an Athlete Breathe Faster and Deeper After Finishing a Race?

An athlete breathes faster and deeper than usual after finishing a race to replenish the oxygen levels in the body and to remove the excess carbon dioxide produced during intense physical activity. During the race, the muscles consume more oxygen and produce more carbon dioxide, leading to an oxygen debt. To compensate for this, the respiratory rate increases to meet the body’s higher oxygen demand and to expel carbon dioxide more efficiently.

2. Similarities and Differences Between Aerobic and Anaerobic Respiration

Similarities:

Both processes release energy.
Both processes involve the breakdown of glucose.

Differences:

Feature	Aerobic Respiration	Anaerobic Respiration
Oxygen Requirement	Requires oxygen	Does not require oxygen
Energy Yield	High amount of energy (38 ATP per glucose molecule)	Low amount of energy (2 ATP per glucose molecule)
End Products	Carbon dioxide and water	Lactic acid (in animals) or ethanol and carbon dioxide (in yeast)
Location	Occurs in the mitochondria	Occurs in the cytoplasm
Efficiency	More efficient	Less efficient

3. Why Do We Often Sneeze When We Inhale Dust-Laden Air?

We sneeze when we inhale a lot of dust-laden air because sneezing is a reflex action that helps to expel irritants from the nasal cavity. Dust particles and other foreign substances stimulate the sensitive mucous membranes in the nasal passages, triggering a sneeze to clear the nasal passages of these irritants.

4. 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-tube B and in C, keep snail and plant both. Which test-tube would have the highest concentration of CO2?

In the experiment with three test-tubes:

Test-tube A (snail only) will have the highest concentration of CO₂ because the snail undergoes respiration, producing CO₂ as a byproduct.
Test-tube B (water plant only) will have a lower concentration of CO₂ because the plant uses CO₂ for photosynthesis during the day, reducing CO₂ levels.
Test-tube C (snail and plant) will have a balanced concentration of CO₂. The snail produces CO₂, which the plant can use for photosynthesis.

Thus, test-tube A will have the highest concentration of CO₂.

5. Tick the Correct Answer

(a) In cockroaches, air enters the body through

(iii) spiracles

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

(ii) lactic acid

(ii) 15–18

(d) During exhalation, the ribs

(ii) move downwards

6. Match the Items in Column I with Those in 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. True or False Statements

(i) During heavy exercise the breathing rate of a person slows down. (False)

(ii) Plants carry out photosynthesis only during the day and respiration only at night. (False)

Corrected statement: Plants carry out photosynthesis during the day and respiration both during the day and night.

(iii) Frogs breathe through their skins as well as their lungs. (True)

(iv) The fishes have lungs for respiration. (False)

Corrected statement: Fishes have gills for respiration.

(v) The size of the chest cavity increases during inhalation. (True)

8. Given below is a square of letters in which are hidden different words related to respiration in organisms. These words may be present in any direction — upwards, downwards, or along the diagonals. Find the words for your respiratory system. Clues about those words are given below the square.

(i) The air tubes of insects – Tracheae

(ii) Skeletal structures surrounding chest cavity – Ribs

(iii) Muscular floor of chest cavity – Diaphragm

(iv) Tiny pores on the surface of leaf – Stomata

(v) Small openings on the sides of the body of an insect – Spiracles

(vi) The respiratory organs of human beings – Lungs

(vii) The openings through which we inhale – Nostrils

(viii) An anaerobic organism – Yeast

(ix) An organism with tracheal system – Insect

9. The Mountaineers Carry Oxygen with Them Because:

(a) At an altitude of more than 5 km there is no air.

(b) The amount of air available to a person is less than that available on the ground.

(d) The pressure of air is higher than that on the ground

Ans: (b) The amount of air available to a person is less than that available on the ground.

Explanation: At higher altitudes, the air pressure is lower, and there is less oxygen available in the atmosphere compared to ground level. Therefore, mountaineers carry oxygen to ensure they get enough oxygen to breathe and function properly.

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