HEREDITY
CROSSOVER
Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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Ratio of crossing over between them
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Cross-over value
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Number of other genes between them
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None of these
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Detailed explanation-1: -Distance between two linked genes is measured in map units which depicts the of crossing over. Q. Assertion :The maximum frequency of recombination, that can result from crossing over between linked genes, is 50 percent. Reason: Linked genes shown higher frequency of crossing over if distance between them is longer.
Detailed explanation-2: -Distance between genes are measured using map units. 1% crossing over between 2 linked genes is 1 map unit.
Detailed explanation-3: -The linkage distance is calculated by dividing the total number of recombinant gametes into the total number of gametes. This is the same approach we used with the two-point analyses that we performed earlier.
Detailed explanation-4: -Solution : Linked genes are those genes which do not show independent assortment but remain together because they are present on the same chromosome. In linkage there is a tendency to maintain the parental gene combination except for occasional crossovers.
Detailed explanation-5: -Centimorgan (cM)/ Map unit is the unit used to express the physical distance between the genes. 1cM equals 1% Recombination frequency. Thus we can calculate the map distance of genes on a chromosome, if we know the percentage of recombinants in the offspring. Q.