NEETZoologyBreathing and Exchange of Gases
Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A): In frogs, dissolved oxygen in water is exchanged through the skin by simple diffusion. Reason (R): On land, the buccal cavity, skin, and lungs act as the respiratory organs in frogs. In the light of the above statements, choose the most appropriate answer from the options given below:
Options
- ABoth (A) and (R) are true and (R) is the correct explanation of (A).
- BBoth (A) and (R) are true but (R) is not the correct explanation of (A).
- C(A) is true but (R) is false.
- D(A) is false but (R) is true.
Correct answer
B. Both (A) and (R) are true but (R) is not the correct explanation of (A).
Step-by-step solution
The Assertion (A) is true because in water, frogs rely on cutaneous respiration where dissolved oxygen is exchanged across the highly vascularized moist skin via simple diffusion. The Reason (R) is also true as adult frogs are amphibious and utilize the buccal cavity, skin, and lungs (pulmonary respiration) for gas exchange when on land. However, (R) does not explain (A). The mechanism of simple diffusion across the skin is a physical process driven by concentration gradients, which is independent of the anatomical