Problem
In squash, two genes control the shape of the fruit. When the dominant allele D, present on chromosome 2 and the dominant allele S, present on chromosome 3, are expressed together, the fruit produced by this plant are disk-shaped. When only one dominant allele is present at either locus, the plant produces spherical fruit. When all alleles are recessive at both loci, the plant produces elongated fruits.
A gardener crossed the following plants (which are homozygous for the genes): Plant with disk-shaped fruit (parent 1) X plant with elongated-shaped fruit (parent 2)
i. Determine the genotypes of the two parental plants (parent 1 and parent 2).
ii. Determine the phenotype(s) and genotype(s) of the F1 plants
iii. What phenotypic proportions (ratio) are expected among the F2? You must include a Punnett square.
iv. Which type of epistasis interaction is seen?
v. Give the genotypic ratio that exists among the disk-shaped fruits seen in the F2 generation