Genotypes and Phenotypes: Exploring Possibilities

How many different genotypes and phenotypes are possible among the blood types of children with IAIB x IAi parents?

A. 2 genotypes; 3 phenotypes

B. 3 genotypes; 4 phenotypes

C. 4 genotypes; 4 phenotypes

D. 3 genotypes; 3 phenotypes

E. 4 genotypes; 3 phenotypes

The correct answer is: E. 4 genotypes; 3 phenotypes

When the genotypes of the parents are IAIB x IAi, there are specific combinations that can result in the genotypes of their children. In this case, the husband's genotype is IAIB and the wife's genotype is IAi.

Upon crossing these genotypes, the possible genotypes for their children are: IAIA, IAIB, IAi, IBIA, IBIB, IBi.

To determine the possible phenotypes, the ABO blood group system comes into play. IA and IB are codominant alleles that express their phenotypes when present together, while i is a recessive allele that only expresses its phenotype in the homozygous form.

As a result, the possible phenotypes among their children are: A (IAIA or IAi), AB (IAIB), B (IBIB or IBi), and O (ii).

Hence, there are four possible genotypes (IAIA, IAIB, IBIB, and ii) and three possible phenotypes (A, AB, and B) among the children of IAIB x IAi parents. Thus, the correct answer is 4 genotypes and 3 phenotypes.