Question

Mendel discovered that yellow seed color in pea plants is dominant to green. what offspring genotype probabilities are expected for a cross between a plant that produces yellow seeds (heterozygous genotype) and one that produces green seeds

Answer 1

Pea plants with yellow color, which are heterozygous have a genotype Aa
Pea plants with green color have a genotype aa (homozygous recessive).
If we cross them:
Parents: Aa x aa
F1 generation: Aa Aa aa aa
This means that half of the offspring will have yellow color (Aa genotype) and half of them will be green (aa genotype).