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Cards In This Set
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What is the significance of meiosis?
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Significance of meiosis: meiosis introduces genetic variability by genetic recombination
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What is genetic recombination?
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Genetic recombination is the product of independent assortment and crossing-over, which introduces genetic variability.
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What are the differences between meiosis and mitosis?
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What does independent assortment generate?
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Independent assortment generates genetic variation.
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How many copies does a cell have of each somatic chromosome?
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A cell has 2 copies of each somatic chromosome- one from mom, one from dad (homologous chromosomes).
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With respect to chromosomes, what function does independent assortment perform?
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Independent assortment shuffles these chromosomes, and then places only one copy of each into the gamete. This way, the gamete may have chromosome 1 from mom, chromosome 2 from dad, chromosome 3 from dad, ... etc.
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Describe the mechanism of independent assortment.
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The mechanism of independent assortment is the following: During metaphase I of meiosis, homologous chromosome pair up along the metaphase line in random orientation - sometimes the mom's chromosome is on the left, sometimes it's on the right. During anaphase I of meiosis, the homologous chromosomes are pulled apart. Those on the left will be put into one daughter cell, those on the right will be put into another.
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Are genes on different chromosomes randomized due to independent assortment?
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Because of independent assortment, genes on different chromosomes are randomized. However, genes on the same chromosome can not be randomized by this mechanism.
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Are genes on the same chromosome linked?
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Genes on the same chromosome are linked to some extent.
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What is "Crossing over"? In which case is crossing over efficient?
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Crossing over is a mechanism that reduces linkage. However, crossing over is only efficient when the genes are physically apart from each other on the chromosome.
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How does crossing over affect the linkage of genes when they are further apart on the chromosome?
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When the genes are further apart on the chromosome, crossing over makes them less linked.
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How does the linkage of genes vary with the distance between them?
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The physically closer the genes are on the chromosome, the more linked they are.
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What is genetic recombination?
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Genetic recombination is the process that introduces genetic diversity into the gametes during meiosis.
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What are the two processes that make up recombination?
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There are 2 processes that make up recombination: independent assortment and crossing over.
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When does crossing over occur?
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Crossing over occurs during prophase I.
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