Suppose a mother carries two recessive genes for freckles (rr) and a father carries one recessive gene for freckles and one dominant gene for clear facial skin (rr). what is the likelihood that their first child will have freckles?

50%

Explanation:

In mendelian inheritance, we can solve this making a punnet square. Given the information, the mother is homocygote to the recessive genes for freckes (rr), and th father is heterocygote, having a dominant copy for clear facial skin, which we will denote Rr. In the punnet sqare attached, we can see that the probability of inheriting the phenotype for the freckles is 50%,. This is a recessive trait, so, for expression it need to be homocygote (rr).