Question

Multiple Choice

1. Which of the following describes lipids?

a source of nutrients for organisms 


energy-storage molecules 


molecules having structural role in membranes 


molecules that are part of hormones and pigments 


all of the above 


2. Molecules bearing both polar and nonpolar groups are said to be which of the following?

a. hydrophilic


b. amphipathic

c. hydrophobic

d. polyfunctional

3. By definition, carbohydrates contain which elements?

carbon and hydrogen 


carbon, hydrogen, and nitrogen 


carbon, hydrogen, and oxygen 


carbon and oxygen 


4. Monosaccharides may link together to form polysaccharides by forming which type of bond?

a. hydrogen

b. peptide


c. ionic


d. glycosidic

5. Which of the following is the name for molecules whose structures are nonsuperimposable mirror images?

structural isomers 


monomers 


polymers 


enantiomers 


Which of the following is an organism that obtains its energy from the transfer of electrons originating from chemical compounds and its carbon from an inorganic source?

a. chemoautotroph

b. chemoheterotroph

c. photoheterotroph

d. photoautotroph

7. A cell might perform anaerobic respiration for which of the following reasons?

It lacks glucose for degradation. 


It lacks the transition reaction to convert 
pyruvate to acetyl-CoA. 


It lacks Krebs cycle enzymes for processing 
acetyl-CoA to CO2. 


It lacks a cytochrome oxidase for passing 
electrons to oxygen. 


8. Which of the following is not an electron carrier within an electron transport system?

a. flavoprotein

b. ATP synthase

c. ubiquinone

d. cytochrome oxidase

9. Which of the following is the purpose of fermentation?

a. to make ATP

b. to make carbon molecule intermediates for anabolism

c. to make NADH

d. to make NAD+

10. Which of the following processes produces hydrogen sulfide?

anoxygenic photosynthesis 


oxygenic photosynthesis 


anaerobic respiration 


chemoautrophy 


11. In which growth phase would you observe the most endospores in a Bacillus cell culture?

death phase 


lag phase 


log phase 


log, lag, and death phases would all have roughly 
the same number of endospores. 


12. Which of the following is the best definition of generation time in a bacterium?

a. the length of time it takes to reach the log phase 


b. the length of time it takes for a population of 
cells to double 


c. the time it takes to reach stationary phase 


the length of time of the exponential phase 


If a culture starts with 50 cells, how many cells will be present after five generations with no cell death?

a. 200

b. 400

c. 1600

d. 3200

14. During which phase would penicillin, an antibiotic that inhibits cell-wall synthesis, be most effective?

death phase 


lag phase 


log phase 


stationary phase 


15. Pseudomonas aeruginosa is a common pathogen that infects the airways of patients with cystic fibrosis. It does not grow in the absence of oxygen. The bacterium is probably which of the following?

an aerotolerant anaerobe 


an obligate aerobe 


an obligate anaerobe 


a facultative anaerobe 


16. Which of the following refers to photosynthesis performed by bacteria with the use of water as the donor of electrons?

a. oxygenic


b. anoxygenic

c. heterotrophic

d. phototrophic

17. Which term best describes the relationship between pathogenic bacteria and humans?
A. amensalism

B. commensalism

C. parasitism

D. predation

18. Which describes bacteria that require low concentrations of oxygen to survive (less than that in the current atmosphere)?

A. facultative anaerobes

B. microaerophiles

C. obligate aerobes

D. obligate anaerobes

19. Cyanobacteria produce which of the following?

A. hydrogen sulfide gas
B. large quantities of ammonia

C. oxygen*
D. sulfuric acid

20.How do Archaea differ from Bacteria?

A. Archaea are found exclusively in extreme habitats.
B. Archaea have ether linkages in their cell membranes.*

C. Archaea have peptidoglycan cell walls.

D. Archaea lack a nucleus.