Week 1
Which individual compared rRNA sequences to generatethe tree of life, establishing the three-domain system?
a. Frederick Griffith
b. Carl Woese
c. Robert Hooke
d. Robert Koch
b. Carl Woese
When bacterial hosts are plentiful, phages employ a _____ lifestyle, and when host numbers are low, they tend toward a _____ cycle
lytic/lysogenic
Which growth phase has the largest increase in cellnumbers per unit of time?
a. death phase
b. exponential phase
c. lag phase
d. stationary phase
b. exponential phase
An organism that oxidizes hydrogen and fixes CO2 is a…
a. Chemoorganoheterotroph
b. Photoorganoheterotroph
c. Chemolithoautotroph
d. Photolithoautotroph
c. Chemolithoautotroph
What was Pasteur's purpose in using a swan-necked flaskrather than a traditional Erlenmeyer flask for his experimentson spontaneous generation?
a. to prevent air from entering
b. to be able to boil and sterilize the liquid medium
c. to prevent large debris and microbes from entering
d. all of the above
c. to prevent large debris and microbes from entering
Teichoic acids are present in the cell walls of
a. gram-positive bacteria.
b. gram-negative bacteria.
c. Archaea.
d. all of the above.
a. gram-positive bacteria.
The exact composition of ____ media is known.____ media inhibit the growth of some microbes.___ media are used to culture fastidious microbes, particularly pathogens.
a. complex / Differential / Selective
b. complex / Enriched / Differential
c. defined / Selective / Enriched
d. defined / Enriched / Differentia
c. defined / Selective / Enriched
n organisms growing by respiration, NADH and FADH2produced during glycolysis and the CAC are reoxidized by
a. fermentation of pyruvate.
b. the electron transport chain.
c. fermentation of citric acid.
d. gluconeogenesis
b. the electron transport chain.
_____ published the first known sketches of molds in the book Micrographia in 1665, making it the first documented description of microorganisms.
a. Antoni van Leeuwenhoek
b. Robert Koch
c. Louis Pasteur
d. Robert Hooke
d. Robert Hooke
Which of the following is NOT a function of pili?
a. cell adhesion
b. defense by poking holes in other cells
c. exchange of genetic material
d. twitching motility
b. defense by poking holes in other cells
Microbes that naturally live within mammalian hosts are
a. psychrotolerant.
b. mesophiles.
c. thermophiles
d. xerophiles
b. mesophiles.
An organism aerobically respires glucose to obtain energy Glucose is the … and oxygen is the …
a. Electron donor/electron acceptor
A capsid is composed of individual units of ____ called ____.
a. polysaccharides / viroids
b. proteins / capsomeres
c. glycolipids / viroids
d. polysaccharides / capsomeres
b. proteins / capsomeres
A product purchased from a drug store guaranteed to kill or inhibit bacteria on skin is best described as a(n)
a. sanitizer.
b. antiseptic.
c. disinfectant.
d. sterilant
b. antseptic
Why do organisms growing by anaerobic respiration generate less ATP than organisms growing by aerobic respiration?
a. They don’t use electron transport to generate proton motiveforce.
b. O2 has the most positive reduction potential and thus is a better electron acceptor.
c. Much less NADH is produced to be used as an electron donor.
d. They don’t generate ATP by oxidative phosphorylation.
b. O2 has the most positive reduction potential and thus is a better electron acceptor.
What principal accomplishment of Pasteur's work wasessential to refute the spontaneous generation theory?
a. bacterial isolation techniques
b. developing nutrient agar plates for culturingmicroorganisms
c. development of the light microscope
d. sterilization
d. sterilization
Archaeal membranes are distinguished from bacterial and eukaryotic membranes by the presence of
a. glycerol molecules.
b. ether-linked lipids.
c. 20-carbon side chains.
d. hydrophobic regions.
b. ether-linked lipids.
A ______ is used to quantify bacteriophages.
Plaque assay
This metabolic classification describes microbes that do not rely on light or inorganic minerals, but instead metabolize organic compounds provided by their environment.
a. Photolithoautotrophs
b. Chemoorganoheterotrophs
c. Chemolithoautotrophs
d. Photoorganoautotrophs
Chemoorganoheterotrophs