NEET BIOLOGY

Detailed explanation-1: -During prophase, the chromosomes condense, the nucleolus disappears, and the nuclear envelope breaks down.

Detailed explanation-2: -During metaphase, the nuclear membrane disappears and the chromosomes become aligned half way between the centrioles.

Detailed explanation-3: -Prophase is the first step of mitosis, during which chromosomes condense and the nuclear envelope dissolves. Metaphase follows prophase.

Detailed explanation-4: -During prophase II, the nuclear envelope and nucleolus disappear. Spindle fibers stretch out from the centrosomes in all directions. The chromatin condenses and the chromosomes become visible under magnification. The sister chromatids are not identical, because of crossing-over during prophase I.

Detailed explanation-5: -Early prophase. The mitotic spindle starts to form, the chromosomes start to condense, and the nucleolus disappears. In early prophase, the cell starts to break down some structures and build others up, setting the stage for division of the chromosomes.