Question

How many linkage groups are found in human males?

• A. 46
• B. 23
• C. 22
• D. 24

Answer 1

The correct option is D 24

A linearly arranged group of linked genes on a single chromosome that is generally inherited in a group (if there is no crossing over between the genes) forms a linkage group. All the genes present on one chromosome constitute one linkage group. Ideally, the number of linkage group = number of haploid chromosome number.

Humans have 23 haploid chromosomes, so ideally the linkage group is 23. In the case of humans, females have 23 linkage groups (22 pairs of autosomes and one pair of homologous sex chromosomes - XX). But in the case of males, it deviates. In males, other than 22 autosomes, there are two different types of sex chromosomes that are not homologous i.e. X and Y. So, 22+1+1 = 24 linkage groups.