AP BIOLOGY

Detailed explanation-1: -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-2: -During prophase, the complex of DNA and proteins contained in the nucleus, known as chromatin, condenses. The chromatin coils and becomes increasingly compact, resulting in the formation of visible chromosomes. Chromosomes are made of a single piece of DNA that is highly organized.

Detailed explanation-3: -Chromatin is in its least condensed stage during the interphase stage. It begins its condensation during the prophase stage and is visible until the end of cell division.

Detailed explanation-4: -Prophase: The nuclear envelope breaks down. The chromatin condenses into chromosomes.

Detailed explanation-5: -During prophase I, the chromosomes condense and become visible inside the nucleus. Because each chromosome was duplicated during the S phase that occurred just before prophase I, each now consists of two sister chromatids joined at the centromere.