Tomato Plants
In tomato plants, round fruit (R) is dominant to oval fruit (r). Pure breeding plants with red and round fruit (FFRR) were crossed to pure breeding plants with yellow and oval fruit (ffrr).
The red and round F1 progeny were then testcrossed to plants that were homozygous recessive for both genes (ffrr) with the following results:
Phenotypes
Number of Offspring
Red and round
2 255
Red and oval
290
Yellow and round
310
Yellow and oval
2 145
Use a Punnett square to determine the expected testcross progeny on the basis of Mendel's Law of Independent Assortment.
a. Record the phenotypes and the phenotype ratio in lowest terms.