An individual has the genotype AbaB Gene loci A and B are 30

An individual has the genotype: Ab/aB. Gene loci (A) and (B) are 30 cM apart. What would the expected proportion of Ab progeny be if a testcross is performed on this individual.

a.) 70%

b.) 35%

c.) 30%

d.) 15%

Please explain how you got your answer! Thanks in advance :)

Solution

Answer: b.) 35%

Gene loci (A) and (B) are 30 cM apart means recombination frequency is 30%

Means 30% recombinant progeny, and remaining 70% parental progeny

Testcross is Ab/aB x ab/ab

Results

Ab= 35% (half of 70% parentals)

aB= 35% (half of 70% parentals)

AB = 15% (half of 30% recombinants)

Ab = 15% (half of 30% recombinants)

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