Question

One pure strain of pea plants developed by Mendel had yellow peas and another strain had
green peas. All the offspring from crosses between the two parental strains (P) of plants
had yellow peas. In these plants, what is the allele for yellow pea color (dominant or
recessive)?

Answer 1

• Allele for yellow pea colour is "Dominant".
Because when two pure strains or homozygous are crossed then only dominant allele is expressed in next generation.
Or. When two homozygous are crossed then in next generation or in heterozygous condition only Dominant allele is expressed or only dominant phenotype is seen.
This is law of dominance.

In this question.
Two homozygous plants are crossed yellow peas (YY) and green peas (yy) and in next generation or im heterozygous condition (Yy) only yellow (dominant) allele is expressed.