AP BIOLOGY

Detailed explanation-1: -Nondisjunction can occur during anaphase of mitosis, meiosis I, or meiosis II. During anaphase, sister chromatids (or homologous chromosomes for meiosis I), will separate and move to opposite poles of the cell, pulled by microtubules.

Detailed explanation-2: -Nondisjunction means that a pair of homologous chromosomes has failed to separate or segregate at anaphase so that both chromosomes of the pair pass to the same daughter cell. This probably occurs most commonly in meiosis, but it may occur in mitosis to produce a mosaic individual.

Detailed explanation-3: -Disjunction normally occurs during the anaphase of mitosis and meiosis (I and II). During the anaphase of mitosis, sister chromatids separate and move towards opposite poles of the cell. In meiosis, disjunction happens when homologous chromosomes move apart toward the opposite poles of the cell in anaphase I.

Detailed explanation-4: -Nondisjunction During Mitosis After DNA replication in the parent cell, each chromosome is composed of two identical sister chromatids. During the anaphase stage of mitosis, these chromatids separate, and one chromatid goes into each daughter cell. However, when nondisjunction occurs, the chromatids do not separate.

Detailed explanation-5: -Nondisjunction, in which chromosomes fail to separate equally, can occur in meiosis I (first row), meiosis II (second row), and mitosis (third row). These unequal separations can produce daughter cells with unexpected chromosome numbers, called aneuploids.