Question 1

A microorganism’s ability to use a harmful pesticide as a source
of carbon and energy is an example of

Select one:

a. chemoautotrophy

b. nitrogen fixation

c. bioremediation

d. photoautotrophy

e. biosynthesis

Question 2

Autotrophs and heterotrophs differ in

Select one:

a. their ability to utilize CO2 as a sole carbon source.

b. their ability to incorporate CO2 into cells.

c. only a few enzymes.

d. their ability to synthesize precursor molecules.

e. their ability to utilize CO2 as a sole energy source.

Question 3

If the amino acid valine constituted approximately 4% of the
total cell protein of a bacterium, how much valine should be added
to a defined medium in order to grow 1 gram of this organism?

Select one:

a. 0.2 mg

b. 2 mg

c. 20 mg

d. 40 mg

e. 200 mg

Question 4

Transport of HPO₄ along with a proton (H⁺)
is an example of

Select one:

a. antiport

b. uniport

c. facilitated diffusion

d. symport

e. group translocation

Question 5

The energy required for transport via ABC transporters is
derived from

Select one:

a. a proton gradient

b. an electrical charge separation across the membrane

c. ATP hydrolysis

d. a symport mechanism

e. a high energy phosphate bond of PEP

Question 6

The spread plate method would clearly be preferred over the pour
plate method when isolating colonies of

Select one:

a. anaerobic bacteria

b. thermophilic bacteria

c. bacteria from temperate lake zones

d. purple non-sulfur bacteria

e. agar-degrading bacteria

Question 7

Enrichment culture procedures for many microorganisms require
intial growth in liquid media, followed by growth on solid media.
The solid media is used to

Select one:

a. provide proper growth conditions.

b. isolate single colonies of the microbes.

c. get rid of competing microorganisms.

d. isolate strict aerobes.

e. enrich for specific nutrients.

Question 8

The optical density of light scattered by bacteria is a very
useful tool for estimating population size. What can alter the
bacteria’s light-scattering properties?

Select one:

a. Cell volume depending on its growth stage

b. The condition of being absent of microorganisms.

c. The amount of light projected from the room.

d. The standard curve

e. Standard deviation from growth curve.

Question 9

What is true about a bacterial colony?

Select one:

a. It arises from an individual cell and represents an isolate
strain.

b. Colonies, and CFU (colony forming units) on streak plates
represent a diverse microbial culture.

c. In order to obtain a colony, on must perform cloning
steps.

d. Axenic cultures to not represent CFUs or colonies.

e. Colonies require differential media in order to separate them
from the population.

Question 10

What is a biofilm?

Select one:

a. All cells in a population achieve a steady state

b. A specialized, surface-attached, collaborative community of
bacteria

c. A complex media made of the chemical building blocks that a
cell needs

d. A type of anaerobic growth chamber.

e. A type of spore