Question

Which of the following statement(s) is (are) true about respiration?
(i) During inhalation, ribs move inward and diaphragm is raised
(ii) In the alveoli, exchange of gases takes place i.e., oxygen from alveolar air diffuses into blood and carbon dioxide from blood into alveolar air
(iii) Haemoglobin has greater affinity for carbon dioxide than oxygen
(iv) Alveoli increase surface area for exchange of gases
(a) (i) and (iv) (b) (ii) and (iii)
(c) (i) and (iii) (d) (ii) and (iv)

NCERT Class X
Science - Exemplar Problems

Chapter_Life Processes

Answer 1

the correct answer is D [2 and 4 ]
in 1st" diaphragm is raised"  is correct but ribs move outward
in 3rd haemoglobin has greater affinity to CO not CO2

Answer 2

(d) (ii) and (iv) are true about respiration.

1. During inhalation, which involves taking in of the air, the capacity of lungs has to increase. In order to do this, diaphragm moves downward and ribs move in outward direction.
2. Haemoglobin is the protein responsible for oxygen transport.
3. It has more affinity for oxygen than carbon dioxide and not vice versa. The protein has high high affinity for carbon monoxide in comparison to oxygen.