AP BIOLOGY

Detailed explanation-1: -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-2: -Anaphase: During anaphase, the centromere splits, allowing the sister chromatids to separate. The kinetochore spindle fibers shorten, allowing for 46 of the newly-freed chromatids to be dragged to one end of the cell and the remaining 46 chromatids to be dragged to the opposite end of the cell.

Detailed explanation-3: -More specifically, in the first part of anaphase-sometimes called anaphase A-the kinetochore microtubules shorten and draw the chromosomes toward the spindle poles.

Detailed explanation-4: -The segregation of the replicated chromosomes is brought about by a complex cytoskeletal machine with many moving parts-the mitotic spindle. It is constructed from microtubules and their associated proteins, which both pull the daughter chromosomes toward the poles of the spindle and move the poles apart.

Detailed explanation-5: -What statement about microtubules during anaphase is true?-Those attached to chromosomes elongate, while those that are unattached shorten.