A woman is a carrier of the X-linked recessive color blindness gene. She has children with a man with normal color vision. Which of the following is true of their offspring?
a. All the males will be color blind.
b. All the females will be carriers.
c. Half the females will be color blind.
d. Half the males will be color blind.

Scientists have recently developed a process by which a skin cell from a human can be triggered to develop into a human heart muscle cell. This is possible because ________.

a. Most cells in the human body contain the genetic instructions for making all types of human cells.

b. A skin cell is produced when all genes in the cell are expressed; turning off some genes in the cell results in a heart cell.

c. Scientists can add new genes to old cells to make them take different forms.

d. A skin cell expresses only recessive alleles, so it can be triggered to produce dominant heart cell alleles.

e. It is easy to mutate the genes in skin cells to produce the alleles required for other cell types.

What is the physical basis for the independent assortment of alleles into offspring?

a. There are chromosome divisions during gamete production.

b. Homologous chromosome pairs are separated during gamete production.

c. Sperm and eggs are produced by different sexes.

d. Each gene codes for more than one protein.

e. The instruction manual for producing a human is incomplete.

Among heritable diseases, which genotype can be present in an individual without causing a disease phenotype in that individual?

a. Heterozygous for a dominant disease

b. Homozygous for a dominant disease

c. Heterozygous for recessive disease

d. Homozygous for a recessive disease

e. All of the above

The pedigree in the figure below illustrates the inheritance of a sex-linked recessive trait. What is the genotype of individual II-5?

a. X^HX^H

b. X^HX^h

c. X^hX^h

d. X^HY

e. X^hY