Question 1

Which of the following best describes the main difference between bacteria and archaea?

Accepted Answer

Bacteria have peptidoglycan in their cell walls, while archaea have unique membrane lipids.

Question 2

A student is using a microscope to observe a stained bacterial sample. Which of the following steps is most critical for differentiating between Gram-positive and Gram-negative bacteria?

Accepted Answer

Application of the decolorizer (alcohol or acetone)

Question 3

Which of the following equations correctly represents the exponential growth of bacteria under ideal conditions?

Accepted Answer

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

Question 4

Which of the following is an example of a physical method for controlling microbial growth?

Accepted Answer

Sterilizing surgical instruments with an autoclave

Question 5

A patient is diagnosed with a viral infection. Which of the following statements about viruses is correct?

Accepted Answer

Viruses require a host cell to replicate their genetic material.

Question 6

Which of the following best describes the role of normal biota in the human body?

Accepted Answer

Normal biota compete with pathogens and can help prevent infections.

Question 7

Which of the following laboratory techniques is most appropriate for isolating a single bacterial species from a mixed culture?

Accepted Answer

Streak plate method

Question 8

A scientist is studying the transfer of antibiotic resistance genes between bacteria. Which process is most likely being investigated?

Accepted Answer

Conjugation

Question 9

Which of the following equations represents the calculation of bacterial generation time ($$g) $$given the number of generations ($$n) $$and total time ($$t$$)?

Accepted Answer

$$g = t / n$$

Question 10

Which of the following is a chemical method for controlling microbial growth?

Accepted Answer

Applying bleach to disinfect a countertop

Question 11

A patient develops a fever and rash after taking antibiotics. Which of the following best explains this phenomenon?

Accepted Answer

The antibiotics disrupted the normal biota, allowing opportunistic pathogens to cause disease.

Question 12

Which of the following best describes aseptic technique in the laboratory?

Accepted Answer

A set of procedures to prevent contamination of cultures and the environment.

Question 13

Which of the following statements about microbial genetics is correct?

Accepted Answer

Plasmids are small, circular DNA molecules that can carry antibiotic resistance genes.

Question 14

A hospital is experiencing an outbreak of a multidrug-resistant bacterial infection. Which of the following laboratory techniques would be most useful for identifying the causative agent?

Accepted Answer

Gram staining and biochemical tests

Question 15

Which of the following best describes selective toxicity in antimicrobial therapy?

Accepted Answer

The drug targets microbial cells without harming host cells.

Question 16

Which of the following equations would you use to calculate the number of generations ($$n) if $$you know the initial number of cells ($$N_0) $$and the final number of cells ($$N_t$$)?

Accepted Answer

$$n = \log_{2}(N_t / N_0$)$$

Question 17

Which of the following is a key difference between prokaryotic and eukaryotic cells?

Accepted Answer

Eukaryotic cells have a nucleus, while prokaryotic cells do not.

Question 18

A laboratory technician is quantifying bacteria in a water sample using the plate count method. Which of the following best describes this technique?

Accepted Answer

Counting only viable (living) cells that form colonies on agar plates.

Question 19

Which of the following is an example of a beneficial interaction between microbes and humans?

Accepted Answer

Production of vitamin K by gut bacteria.

Question 20

A patient is infected with a bacterium that produces a capsule. Which of the following best explains how the capsule contributes to pathogenicity?

Accepted Answer

The capsule helps the bacterium evade phagocytosis by host immune cells.

General Microbiology (BIO 220) – Syllabus and Course Structure Study Notes

Study Guide - Practice Questions

Study Guide - Flashcards