1. In humans most cancers are caused by
A) UV radiation
B) dietary fat
C) X-rays
D) tobacco

2. A DNA microarray is used to
A) detect the location of genes
B) visualize patterns of gene expression
C) isolate mRNA
D) initiate transcription

3. In a multicellular organism cells in one area of the body may regulate gene expression in a distant cell by secretion of
A) antibodies
B) hormones
C) repressor molecules
D) RNA polymerases

4. Which of the following cells is LEAST differentiated?
A) adult stem cells
B) muscle cells
C) nerve cells
D) embryonic stem cells

5. The nucleus of an intestinal cell of a tadpole (baby frog) is transferred to an egg whose nucleus has been removed (nuclear transplantation); some of the eggs will develop into normal tadpoles. This demonstrates
A) that intestinal cells are not differentiated
B) that frogs have large eggs
C) that differentiated cells have retained all of their genetic potential
D) that intestinal cells are embryonic stem cells

6. All of the cells in your body have the same complete set of DNA, however, they have different functions because
A) they contain different chromosomes
B) different genes are switched on and off in each type of cell
C) they contain different operons
D) they contain different sets of genes

7. Regions of noncoding DNA within a gene are called
A) exons
B) oncogenenes
C) transcription factors
D) introns

8. The tumor-suppressor gene is important in the prevention of cancer because it
A) contains multiple promoters for over expression
B) produces gene products that prevent uncontrolled cell growth
C) provides protection from cancer-producing virus infection
D) stimulates production of an oncogene

9. A genetic defect in humans results in the absence of sweat glands. Some men express this defect all over their bodies but in women it is usually expressed differently. A woman with this defect typically has small patches of skin with sweat glands and other patches without. This pattern of sweat gland distribution can best be explained by
A) X chromosome inactivation
B) a mutation
C) a homeotic gene
D) alternative RNA splicing

10. The DNA segment that acts as a switch for turning the lac operon off or on is the
A) promoter
B) regulatory gene
C) lactose genes
D) operator