Question 1

Which of the following best describes a chemoheterotroph?

Accepted Answer

An organism that derives both energy and carbon from organic compounds.

Question 2

A bacterium is placed in a solution with a higher solute concentration than its cytoplasm. What is the most likely effect on the cell?

Accepted Answer

The cell will lose water and shrink due to osmosis.

Question 3

Which of the following is a micronutrient required by bacteria?

Accepted Answer

Zinc

Question 4

Which equation correctly calculates the total number of cells ($$N_t) in a $$bacterial population after $$n$$ generations, starting from $$N_0$$ cells?

Accepted Answer

$$N_t = N_0$ 	imes 2^n$$

Question 5

Which of the following best describes the stationary phase in a bacterial growth curve?

Accepted Answer

Cell division rate equals the cell death rate due to nutrient depletion and waste accumulation.

Question 6

A microbe that thrives at a pH of 1 and is found in acid pools is best classified as a(n):

Accepted Answer

Acidophile

Question 7

Which of the following is NOT a characteristic of biofilms compared to planktonic bacteria?

Accepted Answer

Biofilms consist of single, free-floating cells.

Question 8

Which of the following transport processes requires energy input from the cell?

Accepted Answer

Active transport

Question 9

A bacterium that can survive and grow in the presence of oxygen but does not use it for metabolism is called a(n):

Accepted Answer

Aerotolerant anaerobe

Question 10

Which of the following best explains why obligate anaerobes are killed by oxygen?

Accepted Answer

They lack the enzymes needed to detoxify reactive oxygen species.

Question 11

Which of the following is an example of a mutualistic relationship?

Accepted Answer

A fungus and an alga living together, both benefiting from the association.

Question 12

Which environmental factor is most likely to affect the tertiary structure of bacterial enzymes?

Accepted Answer

pH

Question 13

A bacterium isolated from a hot spring that grows optimally at 90$$^\circC is $$best classified as a(n):

Accepted Answer

Extreme thermophile

Question 14

Which of the following is a trace element important for the function of cytochrome proteins in cell respiration?

Accepted Answer

Iron (Fe)

Question 15

Which process is described by the movement of water across a selectively permeable membrane from an area of low solute concentration to high solute concentration?

Accepted Answer

Osmosis

Question 16

A bacterium that requires high salt concentrations for optimal growth is called a(n):

Accepted Answer

Obligate halophile

Question 17

Which of the following is the correct order of the phases in a typical bacterial growth curve?

Accepted Answer

Lag phase, exponential phase, stationary phase, death phase

Question 18

Which of the following best describes the function of superoxide dismutase in aerobic bacteria?

Accepted Answer

It converts superoxide radicals into hydrogen peroxide.

Question 19

A bacterium that can grow in the presence or absence of oxygen and uses oxygen when available is called a(n):

Accepted Answer

Facultative anaerobe

Question 20

Which of the following methods allows for the quantification of both live and dead bacterial cells in a sample?

Accepted Answer

Direct microscopic count

Microbial Nutrition and Growth: Essential Concepts and Mechanisms

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