AP BIOLOGY

Detailed explanation-1: -The A, B, AB and O blood group types in humans are determined by three alleles of a gene. The gene I, which determines the blood type, exists in three allelic forms, which are IA, IB and i.

Detailed explanation-2: -Phenotypic variation in humans is a direct consequence of genetic variation, which acts in conjunction with environmental and behavioral factors to produce phenotypic diversity. Genetic variants are classified by two basic criteria: their genetic composition and their frequency in the population.

Detailed explanation-3: -Multiple alleles combine in different ways in a population, and produce different phenotypes. These phenotypes are caused by the proteins encoded for by the various alleles. Although each gene encodes for the same type of protein, the different alleles can cause high variability in the functioning of these proteins.

Detailed explanation-4: -Why can multiple alleles result in many different phenotypes for a trait? This can happen because the more allele options for a specific gene the more possible combinations and therefore possible phenotypes the organism that has that gene could inherit.

Detailed explanation-5: -The human phenotypic diversity observed today in human populations is the result of long-term adaptive and selective processes, mainly in response to environmental and cultural changes.