Question 1

Which of the following best describes a chemoautotroph?

Accepted Answer

Uses inorganic chemicals for energy and carbon dioxide as a carbon source.

Question 2

A bacterium is placed in a solution containing 10% salt. The cytoplasm of the bacterium contains 0.9% salt. What will most likely happen to the cell?

Accepted Answer

Water will move out of the cell, causing it to shrink (crenation).

Question 3

Which transport mechanism moves substances against their concentration gradient and requires ATP?

Accepted Answer

Active transport

Question 4

A microbe that grows optimally at pH 8.5 and survives in environments with high pH is best classified as:

Accepted Answer

Alkaliphile

Question 5

Which enzyme is responsible for converting superoxide radicals to hydrogen peroxide in bacteria?

Accepted Answer

Superoxide dismutase (SOD)

Question 6

A facultative anaerobe is placed in an environment with no oxygen. What metabolic process will it most likely use?

Accepted Answer

Fermentation

Question 7

Which of the following is NOT a macronutrient required for microbial growth?

Accepted Answer

Zinc

Question 8

A bacterial population is in the stationary phase of the growth curve. Which of the following best describes this phase?

Accepted Answer

The number of live cells equals the number of dead cells.

Question 9

Which of the following relationships is considered symbiotic and benefits both organisms involved?

Accepted Answer

Mutualism

Question 10

A microbe that requires salt to survive is classified as:

Accepted Answer

Obligate halophile

Question 11

Which method provides a true viable count of bacteria in a sample?

Accepted Answer

Standard plate count

Question 12

If a bacterial culture starts with 100 cells and has a doubling time of 30 minutes, how many cells will there be after 2 hours of exponential growth? Use the formula $$N = N_0$ 	imes 2^n$$, where $$N_0 is $$the initial number of cells and $$n is $$the number of generations.

Accepted Answer

$$N = 100 	imes 2^4$ = 1600$$

Question 13

Which of the following is an example of passive transport that uses carrier proteins but does not require ATP?

Accepted Answer

Facilitated diffusion

Question 14

A microbe that cannot grow above 20ºC and thrives below 15ºC is best classified as:

Accepted Answer

Psychrophile

Question 15

Which of the following is a non-symbiotic relationship where members cooperate and share nutrients?

Accepted Answer

Synergism

Question 16

Which of the following statements about binary fission is correct?

Accepted Answer

It produces genetically identical daughter cells.

Question 17

Which of the following microbes would most likely produce both superoxide dismutase and catalase?

Accepted Answer

Obligate aerobe

Question 18

A bacterial cell is placed in distilled water (0% salt). What is the expected outcome?

Accepted Answer

Water will move into the cell, causing it to burst (lyse).

Question 19

Which of the following is a micronutrient required in trace amounts for microbial growth?

Accepted Answer

Copper

Question 20

A researcher uses a flow cytometer to count bacteria in a mixed population. Which feature does this method provide that others do not?

Accepted Answer

It tags cells with fluorescent substances to record numbers of each type.

Microbial Nutrition, Ecology, and Growth: Study Notes

Study Guide - Practice Questions

Study Guide - Flashcards