Final answer:
The heterozygous genotype among the given options is Aa, which contains one dominant and one recessive allele. Heterozygous individuals producing gametes will have gametes AB, Ab, aB, ab. The ABO blood groups are an example of multiple alleles and codominance, and if heterozygous individuals were favored, the genotype frequencies would change accordingly.
Step-by-step explanation:
The genotype that is heterozygous among the options given is a. Aa. In this genotype, there is one dominant allele (A) and one recessive allele (a), which is the definition of a heterozygous condition. On the other hand, AABB is an example of a homozygous dominant condition because it has two sets of dominant alleles, and 'a' is a homozygous recessive condition with only one kind of allele present and therefore cannot be heterozygous.
The types of gametes produced by an individual with the genotype AaBb would be c. AB, Ab, aB, ab. These represent all the possible combinations of one allele from each gene that can occur during gamete formation. A recessive trait will be observed in individuals that are c. homozygous for that trait (aa), meaning they have two copies of the recessive allele.
The current frequencies of AA and aa genotypes would likely shift if heterozygous individuals (Aa) were favored by natural selection. The observable traits expressed by an organism are identified as its a. phenotype, which is directly influenced by its genotype but also by environmental factors.
When a heterozygous blood type A parent (IAi) and a heterozygous blood type B parent (IBi) mate, one quarter of their offspring are expected to have the AB blood type, which is an example of d. multiple alleles and codominance. This is because the ABO blood groups exhibit both of these genetic phenomena.
In addition to codominance, the ABO blood group antigens are also an example of c. multiple alleles because there are more than two allelic forms (A, B, O) in the population.