9. Which of the following is true of transcription factors?
(A) They control gene expression.
(B) They transcribe ATP into cAMP.
(C) They initiate the epinephrine response in animal cells.
(D) They regulate the synthesis of DNA in response to a signal.
(E) They regulate the synthesis of lipids in the cytoplasm.

5. Carl Woese and collaborators identified two major branches of prokaryotic evolution. What was the basis for dividing prokaryotes into two domains? (A) microscopic examination of staining characteristics of the cell wall (B) metabolic characteristics such as the production of methane gas (C) metabolic characteristics such as chemoautotrophy and photosynthesis (D) genetic characteristics such as ribosomal RNA sequences (E) ecological characteristics such as the ability to survive in extreme environments

6. Mitochondrial DNA is primarily involved in coding for proteins needed for electron transport. Therefore, in which body systems would you expect most mitochondrial gene mutations to be exhibited? (A) the immune system and the blood (B) the excretory and respiratory systems (C) the skin and senses (D) the nervous and muscular systems (E) the circulation system

7. What is a syndrome? (A) a characteristic facial appearance (B) a group of traits, all of which must be present if an aneuploidy is to be diagnosed (C) a group of traits typically found in conjunction with a particular chromosomal aberration or gene mutation (D) a characteristic trait usually given the discoverer's name (E) a characteristic that only appears in conjunction with one specific aneuploidy

8. In the formation of biofilms, such as those forming on unbrushed teeth, cell signaling serves which function? (A) formation of mating complexes (B) secretion of apoptotic signals (C) aggregation of bacteria that can cause cavities (D) secretion of substances that inhibit foreign bacteria (E) digestion of unwanted parasite populations

10. The toxin of Vibrio cholerae causes profuse diarrhea because it (A) modifies a G protein involved in regulating salt and water secretion. (B) decreases the cytosolic concentration of calcium ions, making the cells hypotonic. (C) binds with adenylyl cyclase and triggers the formation of cAMP. (D) signals IP3 to act as a second messenger for the release of calcium. (E) modifies calmodulin and activates a cascade of protein kinases.

11. If you were to observe the activity of methylated DNA, you would expect it to (A) be replicating nearly continuously. (B) be unwinding in preparation for protein synthesis. (C) have turned off or slowed down the process of transcription. (D) be very actively transcribed and translated. (E) induce protein synthesis by not allowing repressors to bind to it.

12. Which of the following is released by platelets in the vicinity of an injury? (A) PDGF (B) MPF (C) protein kinase (D) cyclin (E) Cdk

13. Which of the following is a protein maintained at constant levels throughout the cell cycle that requires cyclin to become catalytically active? (A) PDGF (B) MPF (C) protein kinase (D) cyclin (E) Cdk

14. To view and analyze human chromosomes in a dividing cell, which of the following is/are required? (A) electron microscope (B) radioactive staining (C) fluorescent staining (D) DNA stain and a light microscope (E) a stain particular to human cell

15. Why do RNA viruses appear to have higher rates of mutation? (A) RNA nucleotides are more unstable than DNA nucleotides. (B) Replication of their genomes does not involve proofreading. (C) RNA viruses replicate faster. (D) RNA viruses can incorporate a variety of nonstandard bases. (E) RNA viruses are more sensitive to mutagens.