A tomato with round (A) red (B) fruits crossed with a tomato with pear-shaped (a) yellow (b) fruits.

A tomato with round (A) red (B) fruits crossed with a tomato with pear-shaped (a) yellow (b) fruits. In the offspring, all plants gave round red fruits. What is the genotype of the parents and hybrids?

Since all the offspring obtained from these parent plants is uniform and repeats the traits of one of them, it should be concluded that the genes that determine these traits are dominant and that these genes are homozygous in the genotype of tomatoes with round red fruits. We write such tomatoes, according to the introduced designations, as AABB, they will produce AB germ cells.

Tomatoes with pear-shaped yellow fruits will be aavv, since homozygosity is a necessary condition for the external realization of these characters. These tomatoes produce sex cells ab.

All daughter tomatoes with round red fruits will be AaBb.