In pea plants, yellow seeds (y) are dominant and green seeds (y) are recessive. a pea plant with yellow seeds is crossed with a pea plant with green seeds. the resulting offspring have about equal numbers of yellow and green seeded plants. what are the genotypes of the parents?

To get the result of having 50% of recessive phenotype (green seeds), it is necessary to have a homozygous recessive parent (yy) crossed with a heterozygous parent (Yy) in order to achieve the 50% Yy (yellow, dominant) and 50% (yy, green, recessive).

The Punnett square below illustrates the above result:

y y

Y Yy Yy

y yy yy

So we get 50% Yy (heterogous, yellow dominant) and 50% yy (homozygous recessive, green).