4.1 Stop And Check

Question 0

Suppose you have high sensitivity to the taste of PTV. If your mother has low sensitivity, what (if anything) can you predict about your father’s taste sensitivity?

Answer 0

If your mother has low sensitivity, you must have inherited your high sensitivity gene from your father, so he must have high sensitivity

Question 1

Suppose you have high sensitivity to tasting PTC. If your mother can also taste it easily, what (if anything) can you predict about your father’s ability to taste it?

Answer 1

If your mother has high sensitivity to the taste of PTC, we can make no predictions about your father. You may have inherited a high-sensitivity gene from your mother, and because the gene is dominant, you need only one copy of the gene to taste PTC

Question 2

How does a sex-linked gene differ from a sex-limited gene?

Answer 2

A sex linked gene is on the X or Y chromosome.

A sex limited gene is on an autosomal chromosome, but activated in one sex more than in the other.

Question 3

Suppose someone identified a “gene for” certain aspects of sexual development. In what ways might that statement be misleading?

Answer 3

Almost any characteristic depends on more than one gene, as well as influences from the environment.