Consider the following cross examining four unlinked genes I

Consider the following cross examining four unlinked genes. Identify what proportion of progeny will be phenotypically identical to parent 2? A/a; B/d; e/e times A/a; b/b; E/e

Solution

Assuming that the genes A, B, D and E are completely dominant over a, b, d and e respectively. Cross between these parents will have the progeny with the following genotypes:

Aa*Aa -à A_ (3/4), aa (1/4)

Bb*bb -à Bb (1/2), bb (1/2)

Dd*Dd à D_ (3/4), dd (1/4)

ee*Ee -à Ee (1/2), ee (1/2)

Thus, the proportion of progeny with the phenotype similar to Parent 2 are, ¾*1/2*3/4*1/2 = 9/64