Question

The pedigree chart below shows the individuals in a family who exhibit a certain trait. Based on the info in the chart, which of the following provides the best evidence that this is a recessive trait?

A. Couple 3-4 in the 2nd generation produced children who are identical twins.

B. Couple 1-2 in the second generation produced children who do show the trait.

C. Couple 1-2 in the 1st generation produced children who do show the trait.

D. Couple 3-4 in the 2nd generation produced children who do not show the trait.

Answer 1

The answer is A: Couple 3-4 in the 2nd generation produced children who do not show the trait. If it was a dominant trait, there would be a lot more children with said trait.

Answer 2

The answer is: A. Couple 3-4 in the 2nd generation produced children who are identical twins.

Step-by-step explanation:

As you can see in the graph, the 3-4 couple in the second generation on the right has 2 children who are identical twins.

The answer is: A. Couple 3-4 in the 2nd generation produced children who are identical twins.