Question

Which of the following events takes place during anaphase stage of mitosis?
I. Spindle fibres attach to kinetochores of chromosomes
II. Centromeres split and chromatids separate
III. Chromatids move to opposite poles
IV. Nucleolous, Golgi complex and E.R. reform

• A. I and II only
• B. II and III only
• C. III and IV only
• D. I and IV only

Answer 1

Answer: (B)

II and III only

• Anaphase is characterized by two distinct motions. The first of these, anaphase A, moves chromosomes to either pole of a dividing cell (marked by centrosomes, from which mitotic microtubules are generated and organised). The movement for this is primarily generated by the action of kinetochores, and a subclass of microtubule called kinetochore microtubules.

• The second motion, anaphase B, involves the separation of these poles from each other. The movement for this is primarily generated by the action of interpolar microtubules and astral microtubules.

So, the correct answer is 'II and III only'.