In tomato, the spherical shape of the fruit dominates over the pear-shaped, the red color of the fruit over the yellow.

In tomato, the spherical shape of the fruit dominates over the pear-shaped, the red color of the fruit over the yellow. What segregation by phenotype and genotype can be expected during self-pollination of a tomato plant homozygous for pear-shaped fruit and heterozygous for fruit color?

Let us designate the dominant and recessive alleles of the genes: A – spherical shape of the fruit, a – pear shape, B – red color, b – yellow color of the fruit. F1 genotypes – aaBB, aaBb, aabb in a ratio of 1: 2: 1; phenotypes – plants with red pear-shaped fruits and yellow pear-shaped fruits in a ratio of 3: 1.