AP BIOLOGY

Detailed explanation-1: -The correct option is C. nondisjunction. Sometimes either homologous chromosomes or sister chromatids fail to separate properly during meiosis. This is called nondisjunction, and it produces gametes with an abnormal number of chromosomes.

Detailed explanation-2: -Nondisjunction occurs when homologous chromosomes (meiosis I) or sister chromatids (meiosis II) fail to separate during meiosis. An individual with the appropriate number of chromosomes for their species is called euploid; in humans, euploidy corresponds to 22 pairs of autosomes and one pair of sex chromosomes.

Detailed explanation-3: -During anaphase of the cell cycle, chromosomes are separated to opposite ends of the cell to create two daughter cells. Nondisjunction is the failure of the chromosomes to separate, which produces daughter cells with abnormal numbers of chromosomes. [

Detailed explanation-4: -If sister chromatids fail to separate during meiosis II, the result is one gamete that lacks that chromosome, two normal gametes with one copy of the chromosome, and one gamete with two copies of the chromosome.

Detailed explanation-5: -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.