Question 1

Which of the following best describes a chemoautotroph?

Accepted Answer

Uses carbon dioxide as a carbon source and chemical compounds as an energy source

Question 2

A bacterial cell placed in a hypertonic solution will most likely:

Accepted Answer

Shrivel due to water loss

Question 3

Which equation represents the breakdown of hydrogen peroxide by catalase?

Accepted Answer

$$\mathrm{2H_2O_2 \rightarrow 2H_2O + O_2$}$$

Question 4

Which type of microorganism would most likely be found growing in hot springs with temperatures above 80°C?

Accepted Answer

Hyperthermophiles

Question 5

Why is oxygen deadly for obligate anaerobes?

Accepted Answer

They lack enzymes to neutralize toxic forms of oxygen

Question 6

Which of the following is NOT a function of phosphorus in microbial cells?

Accepted Answer

Component of amino acids

Question 7

A culture medium that contains peptone, beef extract, and agar is best described as:

Accepted Answer

Complex

Question 8

Which biosafety level requires sealed, negative pressure rooms and double HEPA filtration of exhaust air?

Accepted Answer

BSL-4

Question 9

What is the primary reason cardiac nurses and respiratory therapists should care about biofilms?

Accepted Answer

Biofilms are involved in 70% of infections and are highly resistant to microbicides

Question 10

Which of the following best explains why most bacteria grow between pH 6.5 and 7.5?

Accepted Answer

Hydrogen ions interfere with hydrogen bonding in proteins outside this range

Question 11

A facultative anaerobe is best described as an organism that:

Accepted Answer

Can grow with or without oxygen, using fermentation or anaerobic respiration when oxygen is absent

Question 12

Which of the following is a trace element required by microorganisms as an enzyme cofactor?

Accepted Answer

Iron

Question 13

Which method is used to estimate microbial population size by counting colonies after serial dilution?

Accepted Answer

Viable plate count

Question 14

Which equation represents the conversion of superoxide radicals to hydrogen peroxide?

Accepted Answer

$$\mathrm{O_2$^- + O_2$^- + 2H^+ \rightarrow H_2O_2 + O_2$}$$

Question 15

Which of the following is a necessary organic chemical that cannot be synthesized by certain organisms and must be provided in the growth medium?

Accepted Answer

Growth factor

Question 16

Which type of microorganism would be most likely to survive in a high salt environment, such as the Dead Sea?

Accepted Answer

Obligate halophile

Question 17

A bacterial culture is transferred from a death-phase sample into fresh media and grows. What is the best explanation?

Accepted Answer

Some cells remain viable and can resume growth when conditions improve

Question 18

Which of the following is NOT a direct method for measuring microbial reproduction?

Accepted Answer

Turbidity measurement

Question 19

Which of the following best describes the function of a chemostat?

Accepted Answer

Maintains a microbial population in a particular phase of growth by continuously adding fresh medium and removing old medium

Question 20

Which of the following is a real-world application of selective and differential media?

Accepted Answer

Identifying Listeria monocytogenes in clinical samples

Microbial Nutrition and Growth: Study Guide

Study Guide - Practice Questions