Question

what is the probability that the offspring of a homozygous dominant individual (aa) and a homozygous recessive individual (aa) will exhibit the dominant phenotype?

75%

100%

50%

25%

Explanation:

Step1: Determine Parental Genotypes

The homozygous dominant parent has genotype \( AA \), so it can only produce gametes with allele \( A \). The homozygous recessive parent has genotype \( aa \), so it can only produce gametes with allele \( a \).

Step2: Predict Offspring Genotypes

When we cross \( AA \) and \( aa \), all offspring will have the genotype \( Aa \) (since each offspring gets one allele from each parent: \( A \) from \( AA \) and \( a \) from \( aa \)).

Step3: Determine Phenotype of Offspring

The dominant phenotype is expressed when at least one dominant allele (\( A \)) is present. Since all offspring have genotype \( Aa \) (which has the dominant allele \( A \)), all offspring will exhibit the dominant phenotype. So the probability is \( 100\% \).

Answer:

100% (corresponding to the option "100%")