PKU is a recessively inherited disease. Two
parents who have never been diagnosed with the
disorder have a baby that tests positive for PKU.
Which of the following is the best explanation?
Answer

If PKU is a recessively inherited disease, and the baby got it without either parent having it, then you can use a pedigree to figure out what kind of disease it is (whether autosomal or sex-linked). You can automatically cancel out sex-linked because we don't know the gender of the baby, so you can conclude that PKU is autosomal recessive in this family.

Does that make sense?

the oceanic zone is typically defined as the area of the ocean lying beyond the continental shelf, but operationally is often referred to as beginning where the water depths drop to below 100 meters (328 feet), seaward from the coast to the open ocean.

explanation: