The G and B genes are closely linked on the same chromosome

The G and B genes are closely linked on the same chromosome. In this cross, which of the following is true about the gametes produced by the FI progeny: P GGBB X ggbb F1 GgBb GB & gb gametes will outnumber Gb & gB gametes Gb & gB gametes will outnumber GB & gb gametes GB, gB, Gb, & gb gametes will be present in equal numbers D. GB, gB, Gb, & gb will be present in the ratio 9:3:3:1

Solution

When the genes are linked it means that the alleles are present on the same chromosomes.

When this happens, the gametes GB and gb outnumber the Gb and gB gametes, which only occur when the genes are not linked or when there is crossing over takes place.