During a specific phase of mitosis, the spindle fibres pull the sister chromatids towards the opposite poles of the cell. Which of the following events does NOT occur during this phase?

Step-by-step solution

The phase described in the question, where spindle fibres pull chromatids to opposite poles, is anaphase. The key events of anaphase are the splitting of centromeres, separation of chromatids, and their movement to opposite poles. The decondensation of chromosomes and the loss of their individuality is a characteristic event of telophase, which follows anaphase. Answer: Chromosomes decondense and lose their individuality