1. A plant that was homozygous recessive for seed shape was crossed with a plant that was
heterozygous for seed shape. What percentage of the F1 generation will be heterozygous?

50% of the F1 generation will be heterozygous

Explanation:

Let seed shape be denoted by the letter H and h denoting the dominant and recessive traits respectively, the cross between the two parents will be:

Parent 1 = homozygous recessive = hh

Parent 2 = heterozygous = Hh

F1 cross:

                   H              h

h                 Hh            hh

h                Hh             hh

from the cross above, out of 4 offspring in the F1 generation, 2 are heterozygous (Hh) while the remaining 2 are homozygous (hh), so,

2/4 in percentage = 2/4 × 100 = 50%