LABORATORY REVIEW
MITOSIS AND MEIOSIS
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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crossing over
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independent assortment
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gene mutations
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all of the above
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Detailed explanation-1: -During meiosis, homologous chromosomes (1 from each parent) pair along their lengths. The chromosomes cross over at points called chiasma. At each chiasma, the chromosomes break and rejoin, trading some of their genes. This recombination results in genetic variation.
Detailed explanation-2: -Mutations are the original source of genetic variation. A mutation is a permanent alteration to a DNA sequence.
Detailed explanation-3: -Gametes are derived from primordial germ cells specific to the ovary and testes. These primordial germ cells have 2n (46) chromosomes (diploid) but give rise to gametes, which have half that number, n (23) chromosomes (haploid). The process leading to this reduction division is termedmeiosis.