PATHOLOGY

Detailed explanation-1: -In nondisjunction, the separation fails to occur causing both sister chromatids or homologous chromosomes to be pulled to one pole of the cell. Mitotic nondisjunction can occur due to the inactivation of either topoisomerase II, condensin, or separase.

Detailed explanation-2: -Nondisjunction is the failure of paired chromosomes to separate (to disjoin) during meiotic cell division, so that both the parent chromosomes goes to a particular daughter cell while the other daughter cell is devoid of the parent chromosomes.

Detailed explanation-3: -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-4: -Aneuploidy is caused by nondisjunction, which occurs when pairs of homologous chromosomes or sister chromatids fail to separate during meiosis. The loss of a single chromosome from a diploid genome is called monosomy (2n-1), while the gain of one chromosome is called trisomy (2n+1).

Detailed explanation-5: -Disjunction takes place again in Anaphase II of meiosis, when the sister chromatids separate and move to the opposite poles. To compare this with non-disjunction is when this process of separation of chromatids (mitosis) and homologous chromosomes (meiosis) fails to occur.