In Drosophila, the gene for body colour (grey B B\,B is dominant to black bbb) and the gene for wing shape (normal V V\,V is dominant to vestigial vvv) are autosomally linked.
A wild-type heterozygous female was crossed with a double homozygous recessive male. The arrangement of alleles on their chromosomes is shown in the diagram below:
A student collected and counted the resulting offspring of this cross:
- Grey body, normal wings: 415
- Black body, vestigial wings: 385
- Grey body, vestigial wings: 105
- Black body, normal wings: 95
What is the recombination frequency between these two gene loci?
10%10\%10%
20%20\%20%
25%25\%25%
80%80\%80%