Question

Read the assertion and reason carefully to mark the correct option in question.

Assertion: Every chromosome essentially has a kinetochore on the sides of which centromeres are present.

Reason: Based on the position of centromere or primary constriction chromosome can be classified into five types.

• A. If both assertion and reason are true but the reason is not the correct explanation of the assertion.
• B. If assertion is true but reason is false.
• C. If both assertion and reason are false.
• D. If both assertion and reason are true and the reason is the correct explanation of the assertion.

Answer 1

The correct option is C If both assertion and reason are false.

Assertion

Every chromosome essentially has a kinetochore on the sides of which centromeres are present.

Elaboration:

The constricted region of the chromosome is called centromere. It is also called primary constriction. On the sides of the centromere are present proteinaceous, disc-shaped structures called kinetochores. Thus the given assertion is false.

Reason

Based on the position of centromere or primary constriction, chromosome can be classified into five types.

Elaboration:

Based on the position of centromere or primary constriction, chromosome can be classified into four types- metacentric, sub-metacentric, acrocentric, telocentric.

Final answer

(D) If both assertion and reason are false.