PATHOLOGY

Detailed explanation-1: -At the onset of mitosis, the nuclear envelope breaks down and chromatin is progressively converted into a discrete set of rod-shaped structures known as metaphase chromosomes (Fig. 1, metaphase).

Detailed explanation-2: -During prophase, the chromosomes condense, the nucleolus disappears, and the nuclear envelope breaks down.

Detailed explanation-3: -Chromosome condensation, the landmark event at the onset of prophase, often begins in isolated patches of chromatin at the nuclear periphery. Later, chromosome condense into two threads termed sister chromatids that are closely paired along their entire lengths.

Detailed explanation-4: -Diakinesis – Chromosomes become fully condensed and nuclear membrane disintegrates prior to metaphase I.