Why is Quantitative Trait Locus (QTL) mapping done with the F 2 generation? so that individuals used in the mapping will have genotypes in a 3 : 1 ratio so that individuals used in the mapping will have recombinant genotypes so that all individuals used in the mapping will be in HardyWeinberg Equilibrium so that all individuals used in the mapping will be homozygotes so that all individuals used in the mapping will be heterozygotes so that the effect of inbreeding can be quantified.