AP BIOLOGY

Detailed explanation-1: -During prophase, changes occur in both the nucleus and the cytoplasm. In the nucleus, the chromatin fibers become more tightly coiled, condensing into discrete chromosomes observable with a light microscope. The nucleoli disappear. Each duplicated chromosome appears as two identical sister chromatids joined together.

Detailed explanation-2: -Chromatin condensation begins during prophase (2) and chromosomes become visible.

Detailed explanation-3: -During prophase the nucleoli disappear and the chromatin fibers thicken and shorten to form discrete chromosomes visible with the light microscope. Each replicated chromosome appears as two identical chromatids joined at the centromere.

Detailed explanation-4: -In prophase the chromatin begins to coil and condense to form chromosomes. They are coiling because they are preparing to move around. You can begin to notice that each chromosome appears to have two strands (sister chromatids) and that these sister chromatids are attached to each other at a centromere.

Detailed explanation-5: -During prophase, the parent cell chromosomes-which were duplicated during S phase-condense and become thousands of times more compact than they were during interphase.