Question

In what ratio would u find genotypes GG and Gg in f2 progeny?

Answer 1

dominant trait is denoted by capital letters (here G) and the recessive trait by small letters. (here g)

If any dominant gene is present in the organism, the character expressed will be the dominant one.

Eg- If the organism carries Gg gene, the character expressed will be green stem and not purple stem even though the purple gen (g) is present. This is because the recessive cgene gets masked by the dominant one.

i) In F1, the progeny would be Gg, so all would be green stemmed.

ii) If F1 plants self pollinate,

Parents Gg x Gg

Gametes G g G g

G

g

G

GG (Green)

Gg (Green)

g

Gg (Green)

gg (purple)

Ratio of GG: Gg:gg = 1:2:1

Percentage of purple stemmed plants = 25%