LABORATORY REVIEW
MITOSIS AND MEIOSIS
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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contributes to variety
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contributes to the same type of cells over and over
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contributes to nothing
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contributes to the cells with the same amount of DNA
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Detailed explanation-1: -Meiosis also produces genetic variation by way of the process of recombination. Later, this variation is increased even further when two gametes unite during fertilization, thereby creating offspring with unique combinations of DNA.
Detailed explanation-2: -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-3: -Prophase I: The nuclear envelope breaks down. The chromatin condenses into chromosomes. Homologous chromosomes containing the two chromatids come together to form tetrads, joining at their centromeres (2n 4c). This is when “crossing over” occurs, which creates genetic variation.
Detailed explanation-4: -Meiosis is important for three main reasons: it allows sexual reproduction of diploid organisms, it enables genetic diversity, and it aids the repair of genetic defects.
Detailed explanation-5: -The three main methods utilize during meiosis that results in increased genetic variation is crossing over or recombination, random assortment of chromosomes and the random fusion of gametes during fertilization.