$A$ pea plant with blue colour flower denoted by $BB$ is cross-bred with a pea plant with white flower denoted by $ww$.
$(a)$ What is the expected colour of the flowers in their $F_{1}$ progeny?
$(b)$ What will be the percentage of plants bearing white flower in $F_{2}$ generation,when the flowers of $F_{1}$ plants were selfed?
$(c)$ State the expected ratio of the genotypes $BB$ and $Bw$ in the $F_{2}$ progeny.

(N/A) In the $F_{1}$ generation,the cross between $BB$ (blue) and $ww$ (white) results in all offspring having the genotype $Bw$. Since blue is dominant,all $F_{1}$ plants will have blue flowers.
$(b)$ When $F_{1}$ plants $(Bw)$ are self-pollinated,the $F_{2}$ generation follows the Mendelian ratio of $1 BB : 2 Bw : 1 ww$. The plants with the genotype $ww$ will have white flowers. Thus,$1/4$ or $25 \%$ of the plants will bear white flowers.
$(c)$ In the $F_{2}$ generation,the genotypes are $1 BB : 2 Bw : 1 ww$. Therefore,the ratio of the genotypes $BB$ to $Bw$ is $1:2$.