Which term describes a situation where both homozygous phenotypes are expressed in the heterozygote?

Which term describes a situation where both homozygous phenotypes are expressed in the heterozygote?

• A. Polygenic Inheritance
• B. Codominance
• C. Incomplete Dominance
• D. Sex-linked Traits

Answer: (B)

The term that describes a situation where both homozygous phenotypes are expressed in the heterozygote is codominance. In codominance, neither allele is dominant or recessive, which results in both traits being fully expressed at the same time in the phenotype of the heterozygote. A classic example of codominance is seen in blood types, where an individual with one allele for type A blood and another for type B blood expresses both A and B antigens on the surface of their red blood cells, resulting in type AB blood. In contrast, polygenic inheritance refers to the influence of multiple genes on a single trait, leading to a continuous range of phenotypes rather than distinct expressions of both alleles. Incomplete dominance occurs when the heterozygote expresses a phenotype that is a blend of the two homozygous phenotypes, rather than expressing both distinctly. Sex-linked traits involve genes that are located on sex chromosomes and display unique inheritance patterns related to gender but do not specifically refer to the expression of both homozygous phenotypes. Thus, the most accurate term for the situation described is codominance.

The term that describes a situation where both homozygous phenotypes are expressed in the heterozygote is codominance. In codominance, neither allele is dominant or recessive, which results in both traits being fully expressed at the same time in the phenotype of the heterozygote. A classic example of codominance is seen in blood types, where an individual with one allele for type A blood and another for type B blood expresses both A and B antigens on the surface of their red blood cells, resulting in type AB blood.

In contrast, polygenic inheritance refers to the influence of multiple genes on a single trait, leading to a continuous range of phenotypes rather than distinct expressions of both alleles. Incomplete dominance occurs when the heterozygote expresses a phenotype that is a blend of the two homozygous phenotypes, rather than expressing both distinctly. Sex-linked traits involve genes that are located on sex chromosomes and display unique inheritance patterns related to gender but do not specifically refer to the expression of both homozygous phenotypes. Thus, the most accurate term for the situation described is codominance.