Jonathon T. answered • 11/21/22
Experienced Cell Biology Instructor and Practicing PA-C
The parent genotypes are provided for you along the perimeter of the Punnett square. As you can see, both the mother and father are Rr genotypes, or otherwise stated, heterozygous. Since round and wrinkled are completely dominant and recessive alleles respectively, we know that the phenotypic expression of both the parents must be a consequence of the dominant allele they have expressed. The dominant allele R causes a round phenotype, therefore both parents are round. It may seem tricky if you get confused with the square itself and what it represents. The inside squares represent the probable genotypes their offspring would have if they were to reproduce. They would have a 25% chance of having a homozygous dominant, phenotypically round offspring "RR", a 50% change of having heterozygous, phenotypically round offspring "Rr", and a 25% chance of having a homozygous recessive, phenotypically wrinkled offspring "rr". I hope this helps.
