What is the definition of complete dominance in genetics?

What is the definition of complete dominance in genetics?

• A. Complete dominance occurs when the phenotype of the heterozygote is indistinguishable from that of the homozygous dominant individual
• B. Complete dominance results in a phenotype that is a blend of two homozygous phenotypes
• C. Complete dominance occurs when both alleles are equally expressed
• D. Complete dominance only applies to traits that are influenced by a single gene

Answer: (A)

Complete dominance is defined as a genetic scenario where the phenotype of a heterozygous organism—one with two different alleles for a certain trait—exhibits the same phenotype as that of a homozygous dominant organism. This means that the dominant allele completely masks the effect of the recessive allele in the heterozygote, resulting in a uniform expression of the dominant trait. For example, if one allele codes for a purple flower color (dominant) and the other for white flower color (recessive), then a plant with one of each allele (heterozygous) will have purple flowers, the same as a plant that is homozygous for the dominant allele. The other options refer to concepts related to inheritance patterns, but they do not accurately describe complete dominance. The second choice refers to incomplete dominance, where the heterozygote's phenotype is an intermediate blend of the two homozygous phenotypes, leading to a mixture that is distinct from both parent traits. The third option describes codominance, where both alleles are expressed equally, as seen in certain blood types. The last choice suggests that complete dominance applies only to traits influenced by a single gene, which is not strictly true since many traits are

Complete dominance is defined as a genetic scenario where the phenotype of a heterozygous organism—one with two different alleles for a certain trait—exhibits the same phenotype as that of a homozygous dominant organism. This means that the dominant allele completely masks the effect of the recessive allele in the heterozygote, resulting in a uniform expression of the dominant trait. For example, if one allele codes for a purple flower color (dominant) and the other for white flower color (recessive), then a plant with one of each allele (heterozygous) will have purple flowers, the same as a plant that is homozygous for the dominant allele.

The other options refer to concepts related to inheritance patterns, but they do not accurately describe complete dominance. The second choice refers to incomplete dominance, where the heterozygote's phenotype is an intermediate blend of the two homozygous phenotypes, leading to a mixture that is distinct from both parent traits. The third option describes codominance, where both alleles are expressed equally, as seen in certain blood types. The last choice suggests that complete dominance applies only to traits influenced by a single gene, which is not strictly true since many traits are