Which element is required for the formation of the bipolar spindle during cell division?

What occurs during mitosis?

Mitosis results in producing two cells which are similar to each other. What would be the consequence if each of the following irregularities occur during mitosis?
$(a)$ Nuclear membrane fails to disintegrate
$(b)$ Duplication of $DNA$ does not occur
$(c)$ Centromeres do not divide
$(d)$ Cytokinesis does not occur

Choose the correct sequence of two main events in mitosis.

Which of the following processes is not associated with the $S$ phase of the cell cycle?

Which processes are induced during the cell cycle?