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) 

Answer 1

The correct option is: (d) (ii) and (iv)

Explanation:

During inhalation, the diaphragm contracts and moves downward. This increases the space in the chest cavity and thus the lungs expand. The inter coastal muscles contract to pull the rib cage upward and outward.