Question

In a dihybrid cross where two parents (pea plants) differ in two pairs of contrasting traits, that is, pod color and pod shapes color, are crossed. Assuming that the male and female parent were homozygous dominant and recessive for both of these characters respectively, the number of green coloured pod among sixteen progenies of F2 generation will be

• A. 12
• B. 8
• C. 4
• D. 6

Answer 1

The correct option is A 12

Let us assume that G is the allele responsible for green pod color while g is responsible for yellow pod color. I and i are the alleles responsible for inflated and constricted pods respectively.
As given in the question,
genotype of male parent: GGII
genotype of male parent: ggii
Finding out the possible progenies using Punnett square.
$\begin{array}{ccccc}\text{Gametes}& \text{GI}& \text{Gi}& \text{gI}& \text{gi}\\ \text{GI}& \text{GGII}& \text{GGIi}& \text{GgII}& \text{GgIi}\\ & \text{(green, inflated)}& \text{(green, inflated)}& \text{(green, inflated)}& \text{(green, inflated)}\\ \text{Gi}& \text{GGIi}& \text{GGii}& \text{GgIi}& \text{Ggii}\\ & \text{(green, inflated)}& \text{(green, constricted)}& \text{(green, inflated)}& \text{(green, constricted)}\\ \text{gI}& \text{GgII}& \text{GgIi}& \text{ggII}& \text{ggIi}\\ & \text{(green, inflated)}& \text{(green, inflated)}& \text{(yellow, inflated)}& \text{(yellow, inflated)}\\ \text{gi}& \text{GgIi}& \text{Ggii}& \text{ggIi}& \text{ggii}\\ & \text{(green, inflated)}& \text{(green, constricted)}& \text{(yellow, inflated)}& \text{yellow, constricted)}\end{array}$
Green colour (G) is a dominant allele over yellow colour (g) in case of pod color. So, all the progenies with at least one dominant allele (G) will have green colour pod.
As depicted above, out of 16 progenies, 12 are having green colour pods.