AP BIOLOGY

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.