Question

When Mendel crossed yellow- seeded and green- seeded pea plants, all the offspring were yellow seeded. When he took these F1 yellow- seeded plants and crossed them to green- seeded plants, what genotypic ratio was expected

Answer 1

Answer:

genotypic ratio = 2:2

Explanation:

We were being told that when Mendel crossed yellow- seeded and green- seeded pea plants, all the offspring were yellow seeded.

This implies that the Yellow seed trait masked the green seed trait in the F1 generation. The best defination that can be deduced is that;

the yellow-seeded plants are homozygous dominant &

the green-seed pea plants are homozygous recessive

So, let yellow- seeded pea plants= YY

and green- seeded pea plants= gg

i.e YY × gg

  | Y | Y

g | Yg | Yg  

g | Yg | Yg

F₁ = (Yg, Yg, Yg, Yg,) All the offspring were heterozygous yellow seeded plant.

Now, when he crossed the F₁ heterozygous yellow seeded plant with the green- seeded plants; we will have the following result

i.e Yg × gg

  | Y | g

g | Yg | gg  

g | Yg | gg

F₂ = (Yg, Yg, gg, gg)

The F₂  generation would have genotypes of (Yg, and gg) and a genotypic ratio of 2:2