AP BIOLOGY

Detailed explanation-1: -The sister chromatids are pairs of identical copies of DNA joined at a point called the centromere. During anaphase, each pair of chromosomes is separated into two identical, independent chromosomes. The chromosomes are separated by a structure called the mitotic spindle.

Detailed explanation-2: -Sister chromatids separate during anaphase in a three-stage program as directed by interaxis bridges.

Detailed explanation-3: -During anaphase, sister chromatids (or homologous chromosomes for meiosis I), will separate and move to opposite poles of the cell, pulled by microtubules. In nondisjunction, the separation fails to occur causing both sister chromatids or homologous chromosomes to be pulled to one pole of the cell.

Detailed explanation-4: -In anaphase II, the sister chromatids separate and are pulled towards opposite poles of the cell. In telophase II, nuclear membranes form around each set of chromosomes, and the chromosomes decondense.

Detailed explanation-5: -Enzymatic breakdown of cohesin-which linked the sister chromatids together during prophase-causes this separation to occur. Upon separation, every chromatid becomes an independent chromosome. Meanwhile, changes in microtubule length provide the mechanism for chromosome movement.