AP BIOLOGY

Detailed explanation-1: -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.

Detailed explanation-2: -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-3: -Prophase 1 Definition Thus, this stage is important to increase genetic variation. This stage then ends with the disintegration of the nucleolus and the nuclear membrane.

Detailed explanation-4: -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.