1. How can you tell that a trait is controlled by a single gene instead of many genes? A. Single genes can produce many phenotypes in the offspring.

B. Single gene phenotypes can be graphed as bell-shaped curve.

C. Single gene traits usually have only two phenotypes produced, the dominant and the recessive.

D. Singe gene traits can produce an infinite number of phenotypes.

2. Why is colorblindness more common in males than females?

A. Males only have to inherit one copy of the colorblindness gene to have colorblindness.

B. The colorblindness gene is located on the Y chromosome and only males have a Y chromosome.

C. Males normally have more eyesight problems than females.

D. Females only have to inherit one copy of the colorblindness gene to have colorblindness.

3. If two parents both heterozygous for widow's peak produce offspring, what is the probable phenotypic ratio outcome?

A. 3:1
B. 1:2:1
C. 2:2
D.1:1:1:1

4. How is it possible for an offspring to inherit attached earlobes if both parents have free earlobes?

A. The female parent is heterzygous for free earlobes, and the male parent is hybrid for attached earlobes.

B. The parents are both hybrid for the free earlobe trait.

C. One parent is heterozygous for free earlobes, and the other parent is recessive.

D. Both parents are pure bred for free earlobes.

5. A parent heterozygous for both freckles and dimples produces offspring with a parent who is heterozygous for freckles but has no dimples. What is the chance that the offspring will have freckles and no dimples?

A. 25%
B. 1/8
C. 50%
D.3/8