Question

An example of codominance would be:

A. Two individuals heterozygous for brown hair produce a child with blonde hair.
B. Colorblindness.
C. A tall pea plant crossed with a short pea plant produces a medium pea plant.
D. Type A blood crossed with type B blood produces AB blood type.

Answer 1

Option D, 'Type A blood crossed with type B blood produces AB blood type,' is an example of codominance because both the IA and IB alleles are expressed, resulting in blood type AB.

Step-by-step explanation:

An example of codominance would be when both alleles for a gene are expressed equally in the phenotype of the organism. In humans, a classic illustration of codominance is in the ABO blood type system. If an individual possesses one allele for blood type A (IA) and one for blood type B (IB), they will exhibit blood type AB, thereby expressing both A and B antigens on the erythrocytes. Therefore, option D, which states Type A blood crossed with type B blood produces AB blood type, is the correct example of codominance. It's important to note that the alleles IA and IB are codominant with each other, and the presence of these two alleles leads to the expression of both types of antigens on the surface of red blood cells.