In humans, two closely linked genetic loci, each made up of two alleles, compose the histocompatibility locus (HL-A). Paired first and second locus antigens are called haplotypes. The HL-A haplotypes (separated by a semicolon) of a child's parents are given below.Father 3, 25; 7, 12Mother 1, 3; 8, 9Assuming that no cross-over events have occurred, the child's histotype could be which of the following?

In the question presented, the haplotypes of the father are 3, 25 and 7, 12 and the haplotypes of the mother are 1,3 and 8,9. (A haplotype is composed of one allele-antigen-from the one gene of a pair and one allele from the other gene.) Each child of this couple would have inherited one haplotype from each parent. Thus, possible offspring haplotypes are (1) 3,25; 1,3; (2) 3,25; 8,9; (3) 7,12; 1,3; and (4) 7,12; 8,9.