Assertion : The shapes of chromosomes is based on the position of centromere.
Reasons : During anaphase, the chromosomes bends in the region of centromere.

Options

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

Answer

A

Explanation

the position of centromere is fixed for a chromosome. It may lie at the centre (metacentric chromosome), near the centre (submetacentric) subterminal (acrocentric chromosome) or terminal (telocentric chromosome) position. During anaphase the chromosome bends in the region of centreomer. Depending upon the position of centromere an anaphasic chromosome can have V-shape, L-shape, J-shape or I-shape.