Multiple Choice
1. Which of the following describes lipids?
a source of nutrients for organisms â¨
energy-storage molecules â¨
molecules having structural role in membranes â¨
molecules that are part of hormones and pigments â¨
all of the above â¨
2. Molecules bearing both polar and nonpolar groups are said to be which of the following?
a. hydrophilicâ¨
b. amphipathic
c. hydrophobic
d. polyfunctional
3. By definition, carbohydrates contain which elements?
carbon and hydrogen â¨
carbon, hydrogen, and nitrogen â¨
carbon, hydrogen, and oxygen â¨
carbon and oxygen â¨
4. Monosaccharides may link together to form polysaccharides by forming which type of bond?
a. hydrogen
b. peptideâ¨
c. ionicâ¨
d. glycosidic
5. Which of the following is the name for molecules whose structures are nonsuperimposable mirror images?
structural isomers â¨
monomers â¨
polymers â¨
enantiomers â¨
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. â¨
It lacks the transition reaction to convert â¨pyruvate to acetyl-CoA. â¨
It lacks Krebs cycle enzymes for processing â¨acetyl-CoA to CO2. â¨
It lacks a cytochrome oxidase for passing â¨electrons to oxygen. â¨
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 â¨
oxygenic photosynthesis â¨
anaerobic respiration â¨
chemoautrophy â¨
11. In which growth phase would you observe the most endospores in a Bacillus cell culture?
death phase â¨
lag phase â¨
log phase â¨
log, lag, and death phases would all have roughly â¨the same number of endospores. â¨
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 â¨
b. the length of time it takes for a population of â¨cells to double â¨
c. the time it takes to reach stationary phase â¨
the length of time of the exponential phase â¨
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 â¨
lag phase â¨
log phase â¨
stationary phase â¨
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 â¨
an obligate aerobe â¨
an obligate anaerobe â¨
a facultative anaerobe â¨
16. Which of the following refers to photosynthesis performed by bacteria with the use of water as the donor of electrons?
a. oxygenicâ¨
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.
