Consider two genes in the northern flying squirrel (Glaucomys sabrinus). At the first locus, the allele for gray fur (G) is dominant to brown fur (g). At the second locus, the allele for long whiskers (L) is dominant to the allele for short whiskers (l).
A true breeding gray-furred, long-whiskered squirrel is crossed with a true-breeding brown-furred, short-whiskered squirrel, producing a heterozygous F1 with cis arrangement for the alleles of the two genes.
If the F1 heterozygote is test-crossed with a completely recessive brown-furred, short-whiskered flying squirrel, and the following offspring numbers were observed, what could you conclude?
|Gray fur, long whiskers||35|
|Gray fur, short whiskers||15|
|Brown fur, long whiskers||15|
|Brown fur, short whiskers||35|
The genes for fur color and whisker length are linked.
The genes for fur color and whisker length are not linked (i.e., they assort independently).