Question

Consider the following statements:
Assertion (A): Kidneys of vertebrates are called retroperitoneal organs.
Reason (R): They are lined by visceral peritoneum only on their ventral side.
The correct answer is

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

"Retro" means behind. Retroperitoneal = Behind the peritoneum.

Answer 1

The Correct Option is A

Step 1: Analyze Assertion (A):
The kidneys are positioned behind the peritoneum (the membrane lining the abdominal cavity). Organs located in this position are termed retroperitoneal ("retro" = behind). Thus, Assertion (A) is true.
Step 2: Analyze Reason (R):
Because the kidneys lie against the posterior body wall, the peritoneum covers only their anterior (ventral) surface. They are not completely enclosed by the peritoneum. This specific anatomical arrangement—being covered only on the ventral side—is the \textit{definition} and reason for the term "retroperitoneal". Thus, Reason (R) is true and correctly explains why they are called retroperitoneal.
Step 3: Final Answer:
Both statements are true, and R explains A.