Question

which type of dominance describes a situation in which heterozygotes demonstrate a phenotype which is intermediate between the homozygotes? dominant dominance codominance hybrid dominance incomplete dominance

Explanation:

• Co - dominance: In co - dominance, both alleles in a heterozygote are fully expressed simultaneously. For example, in the ABO blood group system, if an individual has the \(I^A\) and \(I^B\) alleles, they have the AB blood type where both \(A\) and \(B\) antigens are present.
• Incomplete dominance: In incomplete dominance, the heterozygote has a phenotype that is intermediate between the two homozygotes. For instance, in snapdragons, a cross between a red - flowered (\(RR\)) and a white - flowered (\(rr\)) plant gives a pink - flowered (\(Rr\)) heterozygote.
• Lethal dominance: Lethal alleles can be dominant or recessive. A dominant lethal allele causes the death of an organism, often early in development. For example, the allele for Huntington's disease is dominant, and while it is not always lethal in the strictest sense (as people can live with the disease for a while), it has a major negative impact on health.
• Hybrid dominance is not a standard term in the context of the types of dominance being asked about here.

Answer:

Incomplete dominance