Question

In a pea plant, spherical seeds(S) are dominant over dented seeds(s). If two plants that are hybrid for spherical seeds (Ss) are crossed, what percentage of the offspring would you expect to have spherical seeds?

A. 75%
B. 25%
C. 50%
D. 100%.

Answer 1

If all the offspring from a test cross between a pea plant with wrinkled peas and a round pea plant are round, then the parent plant with round peas is homozygous dominant.

Step-by-step explanation:

In pea plants, round peas (R) are dominant to wrinkled peas (r). When you do a test cross between a pea plant with wrinkled peas (genotype rr) and a plant of unknown genotype that has round peas, and you end up with three plants, all of which have round peas, you can conclude that the parent plant is homozygous dominant (RR). This is because if the parent plant were heterozygous (Rr), there would be a 50% chance of getting wrinkled peas in the offspring.