AP 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: -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.

Detailed explanation-4: -Prophase is the first stage of mitosis. During this stage, the nucleolus and nuclear membrane disappear. The chromatin in the nucleus condenses and chromosomes become visible.

Detailed explanation-5: -The connection of microtubules to chromosomes is why the nuclear envelope needed to be broken down during prophase. The nuclear envelope would have gotten in the way. The microtubules from opposite ends of a dividing cell connect to the chromosomes during prophase.