What is the expected outcome of a cross between two homozygous individuals with contrasting phenotypes?

What is the expected outcome of a cross between two homozygous individuals with contrasting phenotypes?

• A. No offspring will show dominant phenotypes
• B. All offspring will display the dominant phenotype
• C. Offspring will exhibit a 50/50 phenotype ratio
• D. All offspring will display the recessive phenotype

Answer: (B)

In a cross between two homozygous individuals with contrasting phenotypes, the expected outcome is that all offspring will display the dominant phenotype. This occurs because each parent can only contribute one type of allele to the offspring. When one parent is homozygous for the dominant trait (for example, AA) and the other parent is homozygous for the recessive trait (aa), all offspring will inherit one dominant allele (A) from the dominant parent and one recessive allele (a) from the other parent. As a result, the genotype of all the offspring will be heterozygous (Aa), which expresses the dominant phenotype due to the presence of the dominant allele. This outcome reflects Mendel's principle of dominance, which states that the dominant allele can mask the effect of the recessive allele in a heterozygous individual. Therefore, the correct answer describes the typical result of such a genetic cross accurately.

In a cross between two homozygous individuals with contrasting phenotypes, the expected outcome is that all offspring will display the dominant phenotype. This occurs because each parent can only contribute one type of allele to the offspring. When one parent is homozygous for the dominant trait (for example, AA) and the other parent is homozygous for the recessive trait (aa), all offspring will inherit one dominant allele (A) from the dominant parent and one recessive allele (a) from the other parent. As a result, the genotype of all the offspring will be heterozygous (Aa), which expresses the dominant phenotype due to the presence of the dominant allele.

This outcome reflects Mendel's principle of dominance, which states that the dominant allele can mask the effect of the recessive allele in a heterozygous individual. Therefore, the correct answer describes the typical result of such a genetic cross accurately.