Question

Assertion (A) : A wet dog has a typical odour.
Reason (R) : The typical odour of a wet dog is due to secretion from sebaceous glands of the skin.
In light of the above statements, choose the correct answer from the options given below.

• A. Both (A) and (R) are true and (R) is the correct explanation of (A).
• B. Both (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.

Hint:

The "wet dog" odor is a classic example of volatile organic compounds (VOCs) being released due to moisture-driven evaporation.
The sebaceous glands provide the nutrients, but the water and microbes liberate the smell.

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
The infamous "wet dog smell" is a well-known phenomenon in veterinary science and chemistry, resulting from the interaction of moisture, skin secretions, and resident microbiota.

Step 2: Detailed Explanation:
Let us analyze Assertion (A):
It is an established fact that wet dogs exhibit a distinct, pungent, typical odor. Thus, Assertion (A) is true.
Let us analyze the Reason (R) and its relationship to the Assertion:
The skin of a dog contains numerous sebaceous glands that secrete a lipid-rich substance called sebum.
This sebum contains organic compounds like volatile fatty acids.
However, the dry sebum itself does not have a very strong odor.
The odor is primarily generated when water (moisture) acts as a solvent, breaking down the chemical bonds of these sebum lipids and allowing resident microorganisms (bacteria and yeast) on the dog's skin to metabolize them into highly volatile compounds (such as organic acids, aldehydes, and ketones).
When the water evaporates, it carries these volatile compounds into the air, leading to the intense smell.
Therefore, while the sebaceous secretions are indeed the source of the chemical precursors of the smell (making statement R true), the reason a wet dog smells specifically when wet is the physical and biochemical role of water and microbial action in liberating these volatiles.
Thus, both (A) and (R) are true, but (R) is not the correct or complete explanation of why a wet dog smells specifically.

Step 3: Final Answer:
Hence, the correct option is (B).