Both Peggy and Bob are farsighted.If their child is nearsighted,then it follows that
A)both Peggy and Bob lack a gene for farsightedness.
B)only Peggy has a gene for farsightedness.
C)only Bob lacks a gene for nearsightedness.
D)both Peggy and Bob have a gene for nearsightedness.

Question

Quizplus · Accepted Answer

Nearsightedness is a dominant trait, meaning that if a child inherits one copy of the gene for nearsightedness from either parent, they will be nearsighted. Since both Peggy and Bob are farsighted, it means that they each have two copies of the gene for farsightedness. If their child is nearsighted, it means they must have inherited at least one copy of the gene for nearsightedness from either Peggy or Bob. Therefore, both Peggy and Bob have at least one copy of the gene for nearsightedness.

Both Peggy and Bob Are Farsighted