Which are different forms of the same gene?

Which describes the law of segregation?

A plant that has round and yellow seeds (RrYy) is crossed with a plant that has round and yellow seeds (RrYy). What is the ratio of the offspring that will have round and yellow seeds?

Key: R = round

r = wrinkled

Y = yellow

y = green

The diagram represents a dihybrid cross between two pea plants heterozygous for both seed color and seed shape. What is the phenotypic ratio of the offspring?

Pea plants can have yellow seeds or green seeds. Which conclusion about the meaning of Y is correct if the allele combination Yy is for yellow seeds?