Question

Given below are two statements, one is labelled as Assertion (A) and other one labelled as Reason (R).
Assertion (A): Capillaries are thin walled having a single cuboidal epithelium.
Reason (R): Blood flows through the capillaries under high pressure.
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:

Capillary walls are made of flattened squamous cells, not cuboidal cells.

Answer 1

The Correct Option is D

Step 1: Understanding the Concept
Capillaries are the thinnest blood vessels and take part in exchange of materials with tissues.

Step 2: Check the Assertion
A capillary wall is a single layer of flattened squamous endothelial cells on a basement membrane. It is not cuboidal, so (A) is false.

Step 3: Check the Reason
Blood enters capillaries with a hydrostatic pressure that pushes fluid out to form tissue fluid. In this sense the Reason is taken as true.

Step 4: Conclusion
(A) is false but (R) is true.

Final Answer:
The Assertion is false but the Reason is true. \[ \boxed{\text{(D) }\text{(A) is false but (R) is true.}} \]