Question

The genotype of green stemmed tomato plants is denoted as GG and that of purple stemmed tomato plants is denoted as gg. When these two are crossed with each other:
(a) What colour of stem would you expect in the F1 progeny?
(b) Give the percentage of purple stemmed plants if F1 plants are self pollinated.
(c) In What ratio would you Find the genotypes GG and gg in the progeny?
Draw flow chart in support of your answer.

Answer 1

(a) green will produce in F1 generation

(b) since the purple stemmed plants will not appear in F1 progeny because greenGG is dominant so ,green will appear ,hence percentage is 0

(c) 3/1 is appear in GG and gg in the progeny

Answer 2

Answer :-

Crossing:

Parents: GG gg

↓ ↓

Gamete: G g

↓

F₁ generation: Gg (G×g)

↓

F₂ generation: GG ; Gg ; Gg ; gg

(selfing ; Gg×Gg)

i) When green stemmed tomato is crossed with purple stemmed tomato then it gives Green stemmed tomato because G is dominant over g in F₁ generation/progeny.

ii) If F₁ generation are self pollinated (selfing) then, the percentage of Purple stemmed tomato is 25% and Green stemmed tomato is 75%.

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

iv) Law of segregation.