Question

In pea plants, the trait for round seeds is dominant over the trait for wrinkled seeds. If a pure dominant plant with round seeds is crossed with a plant having wrinkled seeds, what can be predicted about the offspring plants?

A. All offspring will have round seeds.
B. All offspring will have wrinkled seeds.
C. All offspring will have a mix of round and wrinkled seeds.
D. All offspring will have a different trait not related to seed shape.

Answer 1

When a homozygous dominant plant with round seeds (RR) is crossed with a homozygous recessive plant with wrinkled seeds (rr), all offspring will have round seeds, as the round seed trait is dominant.

Step-by-step explanation:

When a pure dominant pea plant with round seeds is crossed with a plant with wrinkled seeds, we can predict the outcome for the offspring plants based on Mendelian genetics.

For the gene that determines seed shape in pea plants, round seeds (R) are dominant over wrinkled seeds (r).

If we cross a homozygous dominant plant (RR) with a plant with wrinkled seeds (rr), which is necessarily homozygous recessive, all the offspring will inherit one dominant allele R from the round-seeded parent, and one recessive allele r from the wrinkled-seeded parent, resulting in a heterozygous (Rr) genotype, which expresses the dominant trait. Thus, A. All offspring will have round seeds is the correct prediction for the phenotypes of the offspring plants.