Updated By SaraNextGen

On March 11, 2024, 11:35 AM

Question 1:

Why does an athlete breathe faster and deeper than usual after finishing the race?

Answer:

Anathlete needs to supply extra energy to his muscle cells which have worked hard during running. For this, he breathes faster and deeper so that more oxygen is supplied to the cells. This speeds up the breakdown of food and as a result, more energy is released.

Question 2:

List the similarities and differences between aerobic and anaerobic respiration.

Answer:

Similarity between aerobic and anaerobic respiration:

In both aerobic and anaerobic respiration, the food is broken down to release energy.

Differences between aerobic and anaerobic respiration:

Question 3:

Why do we often sneeze when we inhale a lot of dust-laden air?

Answer:

Sneezing expels the foreign particles from the inhaled air, so that only clean air enters our body. It usually occurs because of the irritation in the upper breathing passage. This irritation happens when we inhale some unwanted particles and they get trapped in our nasal cavity. Smoke, dust, pollen, etc. are some of the unwanted particles that may cause sneezing.

Question 4:

Take three test-tubes. Fill 3/4th 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?

Answer:

Test tube A will have the highest concentration of CO_2. This is because test tube A contains snail. Snail is an organism that breathes in O₂ and breathes out CO₂. Hence, CO₂ concentration increases in test tube A.

Test tube B contains a water plant, which takes in CO₂ for food synthesis and gives out O₂. Hence, more O₂ concentration is found in test tube B.

Test tube C contains both a snail and a plant. The CO₂ produced by the snail is utilized by the plant for its food synthesis and the O₂ released by the plant is utilized by the snail for respiration.

Therefore, test tube A has the highest concentration of CO₂.

Question 5:

Tick the correct Answer:

(a) In cockroaches, air enters the body through

(i) lungs

2. gills

(iii) spiracles

(iv) skin

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

(i) carbon dioxide

2. lactic acid

2. alcohol

(iv) water

(c) Normal range of breathing rate per minute in an average adult person at rest is

(i) 9-12

(ii) 15-18

(iii) 21-24

(iv) 30-33

(d) During exhalation, the ribs

(i) move outwards

(ii) move downwards

(iii) move upwards

(iv) do not move at all

Answer:

(a) In cockroaches, air enters the body through

(i) lungs

2. gills

(iii) spiracles √

(iv) skin

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

(i) carbon dioxide

2. lactic acid √

2. alcohol

(iv) water

(c) Normal range of breathing rate per minute in an average adult person at rest is

(i) 9-12

(ii) 15-18 √

(iii) 21-24

(iv) 30-33

(d) During exhalation, the ribs

(i) move outwards

(ii) move downwards √

(iii) move upwards

(iv) do not move at all

Question 6:

Match the items in Column I with those in Column II:

Answer: