Question

These little bunnies (A, B, and C) were born in the same litter to the same parents, but they have different traits for the feature of ear thickness. Bunny A has thick ears, bunny B has average ears, and bunny C has thin ears. How did these bunnies end up with ear thicknesses that are different from one another even though they have the same parents? How did the gene combinations result in the different traits?

Answer 1

Answer/Explanation:

We each inherit 2 versions of a gene from our parents: one from the mother and one from the father.

However,  our mother and father also have 2 versions of each gene. So the one we end up inheriting is random, like a coin toss. This is true for each parent.

Say the mother has one version of the gene that gives thick ears (A), and one version of the gene that gives thin ears (a). So she is Aa.

Say the father has the same, and he is also Aa.

The father can pass on either A or a, and the mother can pass on either A or a.

So their children can either be AA, Aa, or aa. AA would give thick ears, and aa would give thin ears. Aa gives an intermediate thickness like in bunny B. This is an example of incomplete dominance