AP BIOLOGY

Detailed explanation-1: -If we cross a heterozygous individual with a homozygous dominant individual, there would be a 50% probability that offspring would be heterozygous. There would also be a 50% probability that offspring would be homozygous dominant, and a 0% probability that the offspring would be homozygous recessive.

Detailed explanation-2: -The answer is 50%. Assume that the homozygous recessive trait is denoted by aa and the heterozygote is Aa.

Detailed explanation-3: -In a test cross, the dominant-expressing organism is crossed with an organism that is homozygous recessive for the same characteristic. If the dominant-expressing organism is a homozygote, then all F1 offspring will be heterozygotes expressing the dominant trait (Figure 8.8).

Detailed explanation-4: -Offspring homozygous for both recessive traits There is only one of 16 possible combinations with this genotype. The predicted fraction is therefore 1/16.