a) In the F2 generation the ratio of progeny developed is of 13 white to 3 red flowers, which indicates that the double recessive is not the red phenotype. The general formula for color is represented by a/a; B/-. The cross between two pure lines and their genotypes are given below.
A/A; B/B X a/a; b/b
F1:
A/a; B/b
F2:
9 A/-; B/- white
3 A/-; b/b white
3 a/a; B/- red
1 a/a; b/b white
b) Cross 1:
A/A; B/B X A/a; B/b
Progeny obtained are as follows:
A/-; B/- white
Cross 2:
a/a; b/b X A/a; B/b
Progeny obtained are as follows:
¼ A/a; B/b white
¼ A/a; b/b white
¼ a/a; b/b white
¼ a/a; B/b red