Which statement describes crossing over as it occurs in meiosis?
Question
Which statement describes crossing over as it occurs in meiosis?
Solution
Crossing over in meiosis is a process where homologous chromosomes pair up and exchange segments of their genetic material. This occurs during the prophase I stage of meiosis. Here are the steps:
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Homologous chromosomes (one from each parent) pair up in a process called synapsis, forming a structure known as a tetrad. This tetrad contains four chromatids.
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While in synapsis, the chromatids of the homologous chromosomes come into contact at various points along their length. These points are known as chiasmata.
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At these chiasmata, the chromatids break and then reconnect to the other chromatid. This is the actual "crossing over" or recombination event.
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The chromosomes remain in synapsis until they are ready to be pulled apart during anaphase I. When they are pulled apart, the recombined chromosomes are separated.
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The result of crossing over is that each of the resulting chromosomes is a unique mixture of the parent's genes, rather than a duplicate of one parent or the other. This contributes to genetic diversity in sexually reproducing populations.
Similar Questions
When does 'crossing over' occur?Group of answer choicesTelophase of mitosisProphase I of meiosisAnaphase II of meiosisMetaphase II of meiosis
The first phase of meiosis, during which crossing-over occurs, is I.
Crossing over occurs between homologous chromosomes.Group of answer choicesmeiosis onlyneither mitosis nor meiosisboth mitosis and meiosismitosis onlyNext
The stage of meiosis in which chromosomes pair and cross over is:
What is the significance of crossing over during meiosis?*1 pointCrossing over increases genetic diversity by exchanging genetic material between homologous chromosomes.Crossing over ensures that sister chromatids are separated during anaphase II.Crossing over helps to condense chromosomes during prophase.Crossing over prevents the formation of gametes.
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