NEET BIOLOGY

Detailed explanation-1: -During prophase II, chromosomes condense and the nuclear envelope breaks down, if needed. The centrosomes move apart, the spindle forms between them, and the spindle microtubules begin to capture chromosomes.

Detailed explanation-2: -During prophase, chromatin condenses into chromosomes, and the nuclear envelope, or membrane, breaks down. In animal cells, the centrioles near the nucleus begin to separate and move to opposite poles (sides) of the cell.

Detailed explanation-3: -Prophase II encompasses four different mechanisms; namely the tight wrapping of DNA into chromosomes, the dissolving of the nuclear membrane, migration of the centrosomes (when present), and the reconstruction of the spindle apparatus.

Detailed explanation-4: -At the end of prophase I, the nuclear membrane breaks down, the centrosomes have migrated to the opposite ends of the cell, and the spindle apparatus is being formed. This is followed by metaphase I. During this stage, the spindle fibers, or microtubules, attach to the centromere of each chromosome.