Practice question

Linkage group defined as set of genes whose loci reside on same physical chromosome and tend to be inherited together unless recombination separates them. Entire chromosome contains one linkage group because DNA molecule continuous and centromere ensures coordinated segregation. Counting distinct chromosomes in haploid complement therefore equals number linkage groups. Each linkage group corresponds to chromosome pair in diploid organism. Principle holds across species: Drosophila 2n=8 has 4 groups, pea 2n=14 has 7 groups, reflecting haploid number rather than gene number or allele diversity per locus.