Question

Assertion (A): Human red blood cells are circular and biconcave.

Reason (R): This shape prevents the easy passage of these cells through blood capillaries.

विकल्प

• A is True and R is False.

• A is False and R is True.

• Both A and R are True.

• Both A and R are False.

Answer 1

Both A and R are True.

Explanation:

A is correct. Red blood cells are round and biconcave. This shape improves both flexibility and gas-exchange efficiency. R is false. The biconcave shape maximises surface area for gas exchange, rather than facilitating passage through capillaries.