AP BIOLOGY

Detailed explanation-1: -Likewise, abnormal separation can occur in meiosis when homologous pairs fail to separate during anaphase I. This also results in daughter cells with different numbers of chromosomes. The phenomenon of unequal separation in meiosis is called nondisjunction.

Detailed explanation-2: -Nondisjunction is the failure of the chromosomes to separate, which produces daughter cells with abnormal numbers of chromosomes. [

Detailed explanation-3: -Nondisjunction during Meiosis I means two homologous chromosomes will stay together and both move into the same cell. In the figure labelled “Nondisjunction at Meiosis I” the largest chromosomes fail to separate; both move into the left daughter cell together.

Detailed explanation-4: -This real possibility is usually due to mistakes during meiosis; the chromosomes do not fully separate from each other during sperm or egg formation. Specifically, nondisjunction occurs when homologous chromosomes or sister chromatids fail to separate during meiosis, resulting in an abnormal chromosome number.

Detailed explanation-5: -However, when nondisjunction occurs, the chromatids do not separate. The result is that one cell receives both chromatids, while the other cell receives neither. Each daughter cell then has an abnormal number of chromosomes when mitosis is complete; one cell has an extra chromosome, while the other is missing one.