A student crosses two homozygous plants, one with green pods and the other with yellow pods. If yellow is dominant over green, what phenotypic results will the student find in the offspring?
A.
100% yellow
B.
100% green
C.
75% yellow, 25% green
D.
75% green, 25% yellow
The correct answer is A. 100% yellow.
If yellow is dominant over green, it means that if an individual carries at least one yellow allele, its phenotype will be yellow. Homozygous plants have two identical alleles for a particular trait. In this case, the homozygous plant with yellow pods will have two yellow alleles (YY), and the homozygous plant with green pods will have two green alleles (gg).
When these two plants are crossed, all of the offspring will inherit a yellow allele from the yellow pod parent. Since yellow is dominant over green, all of the offspring will have the yellow phenotype, even if they carry a green allele. Therefore, the phenotypic results will be 100% yellow.