Question

The genetic distance between genes $A$ and $B$ is $10cM$. An organism with $Ab$ combination of the alleles is crossed with the organism with $aB$ combination of alleles. What will be the percentage of the gametes with $AB$ allele combination produced by an $F1$ individual?

• A. $1$
• B. $5$
• C. $10$
• D. $50$

Answer 1

The correct option is B $5$

The genetic distance between genes A and B is 10 cM. It means, the recombination frequency is 10%. If the cross is made between two parents with genotype Ab and aB, out of their progeny, 10% will be recombinant type (that is AB and ab) and 90% will be parental type (that is aB and Ab). AB allele represents half of the recombination type, that is 5%.

Thus, the correct answer is option B.