CELL DIVISION
MEIOSIS AND GENETIC VARIATION
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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an inherited mutation carried in an egg or a sperm
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an error in meiosis where chromosomes fail to separate
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when chromosomes fuse together during mitosis
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when homologous chromosomes trade segments
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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: -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: -1: Nondisjunction in Meiosis: Nondisjunction occurs when homologous chromosomes or sister chromatids fail to separate during meiosis, resulting in an abnormal chromosome number. Nondisjunction may occur during meiosis I or meiosis II.
Detailed explanation-4: -Nondisjunction is the failure of homologous chromosomes to disjoin correctly during meiosis. This results in the production of gametes containing a greater or lesser chromosomal amount than normal ones.