In maize (corn), assume that the genes A and B are linked and 30 map units apart. If a plant of Ab/aB is selfed, what proportion of the progeny would be expected to be of ab/ab genotype?A)2.25% B)15% C)9%D)30%E)4.5%

2.25%.

Explanation:

The recombination progeny occur due to the crossing over of the homologous chromosomes. The linked gene is 30 map units apart and the recombination frequency is 30.

If a plant of Ab/aB is selfed then the progeny obtained is as follows: Ab – parental – 35%, aB – parental – 35%, AB – recombinant – 15%  and ab – recombinant – 15%. The cross between the F2 progeny with aabb is ( 0.15 × 0.15) = 0.0225 or 2.25%.

Thus, the answer is option (A).