1. The process by which the cell membrane invaginates to produce a deep, narrow furrow that

eventually fuses into a small cytoplasmic vacuole containing fluid is called

A. exocytosis

B. phagocytosis

C. pinocytosis

D. None of these choices is true

2. The nucleotide base that is present in RNA but not in DNA is

A. adenine

B. guanine

C. cytosine

D. thymine

E. uracil

3. The final product of anaerobic respiration is/are

A. glucose

B. pyruvic acid

C. lactic acid

D. carbon dioxide and water

4. Which of the following organs has an almost absolute requirement for blood glucose as its

energy source?

A. heart

B. brain

C. skeletal muscles

D. liver

5. In terms of energy production, the Krebs cycle is significant because it

A. produces glucose

B. functions in oxidative phosphorylation

C. produces large amounts of NADH + H+ and FADH2

D. directly produces large amounts of ATP

6. Which of the following statements about end-product inhibition is true?

A. A later product of a metabolic pathway inhibits activity of an enzyme involved in an earlier

reactionin that pathway.

B. It involves allosteric interaction between an intermediate in a metabolic pathway and an

enzyme.

C. It represents a form of negative feedback.

D. All of these choices are true.

7. Which of the following statements about the cell membrane is TRUE?

A. It is composed of a double layer of phospholipids with the polar groups facing the inside and

outside of the membrane.

B. It is composed of a double layer of phospholipids with the polar groups facing the center of

the membrane.

C. The membrane is covered on both sides by a continuous layer of proteins.

D. The cell is a rigid structure.

8. As the pH or temperature is changed from the optimum for a particular enzyme, the activity

of that enzyme decreases due to

A. disruption of the amino acid sequence

B. alteration of the three-dimensional structure of the enzyme

C. alteration in the shape of the substrate

D. locking of the enzyme-substrate complex

9. Mitochondria

A. serve as sites for cellular energy

B. may vary in size and shape

C. have double membranes

D. All of these choices are true

10. Which of the following best describes the role of oxygen in body cells?

A. It is needed for glycolysis.

B. It combines with glucose to form carbon dioxide and water.

C. It transfers energy from glucose to ATP.

D. It is the final electron acceptor from the electron transport chain of cytochromes.