A blue colour flower plant denoted by BB is crossbred with that of white colour flower plant denoted by bb. (a) State the colour of flower you would expect in their F1 generation plants. (b) What must be the percentage of white flower plants in F2 generation if flowers of F1 plants are self-pollinated ? (c) State the expected ratio of the genotypes BB and Bb in the F2 progeny.

(a) Colour of F1 generation flowers: All plants in the $F_1$ generation will have blue flowers. This is because the allele for blue colour ($B$) is dominant over the allele for white colour ($b$), resulting in the heterozygous genotype $Bb$.

(b) Percentage of white flower plants in F2 generation: When $F_1$ plants ($Bb$) are self-pollinated ($Bb \times Bb$), the $F_2$ generation will have a phenotypic ratio of 3 blue to 1 white. Therefore, the percentage of white flower plants ($bb$) will be 25% (or $\frac{1}{4} \times 100\%$).

(c) Expected ratio of genotypes BB and Bb in F2 progeny: The genotypic ratio in the $F_2$ generation is $1\text{ BB} : 2\text{ Bb} : 1\text{ bb}$. Thus, the ratio of the genotypes $BB$ to $Bb$ is 1:2.