Let's Learn about Pea Plants!

What determines the texture of pea plants?

In pea plants, a single gene controls pea texture. Smooth (S) peas are dominant over wrinkled (s) peas. If a plant with smooth peas is crossed with a plant with wrinkled peas, what are the genotypes of the parent plants?

Answer:

The genotypes of the parent plants are SS and ss.

Pea plants have a gene that controls their texture, with smooth peas being dominant over wrinkled peas. When a plant with smooth peas (genotype SS) is crossed with a plant with wrinkled peas (genotype ss), the progeny will have a mix of genotypes.

In this scenario, 252 progeny are smooth (genotype SS) and 247 are wrinkled (genotype ss). This indicates that the parent plants must have been heterozygous (Ss) for the gene controlling pea texture.

When a plant with genotype SS is crossed with a plant with genotype ss, the possible genotypes of the offspring are SS, Ss, and ss. The results of 252 smooth and 247 wrinkled progeny fit the expected outcome.

Therefore, the genotypes of the parent plants in this cross are SS and ss, resulting in a combination that produced the observed ratio of smooth and wrinkled peas in the progeny.