Question 1

Which of the following best describes the difference between prokaryotic and eukaryotic cells?

Accepted Answer

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

Question 2

Which statement correctly defines an opportunistic pathogen?

Accepted Answer

A microbe that is harmless under normal conditions but can cause disease when the host's defenses are compromised.

Question 3

Louis Pasteur disproved spontaneous generation by using which experimental setup?

Accepted Answer

S-necked flasks that prevented airborne microbes from contaminating sterile broth.

Question 4

Which of the following is NOT one of Koch’s postulates?

Accepted Answer

The microorganism must be able to survive outside the host for at least 24 hours.

Question 5

Which scientist is credited with introducing hand washing to reduce hospital-acquired infections?

Accepted Answer

Ignaz Semmelweis

Question 6

A biofilm is best described as:

Accepted Answer

A slimy, multi-layered community of microbes adhering to a surface.

Question 7

Which of the following is an example of mutualism in host-microbe interactions?

Accepted Answer

Lactobacilli lowering vaginal pH and preventing vaginitis.

Question 8

What is the main function of autoinducers in biofilm formation?

Accepted Answer

They signal microbes to change gene expression and produce extracellular polymeric substances (EPS).

Question 9

Which of the following is a consequence of disrupting normal microbiota with antibiotics?

Accepted Answer

Overgrowth of opportunistic pathogens such as Candida or Clostridioides difficile.

Question 10

Which of the following is NOT a goal of aseptic technique in healthcare?

Accepted Answer

Ensuring all surfaces and instruments are completely sterile at all times.

Question 11

Which of the following best describes the scientific method?

Accepted Answer

A systematic approach involving observation, hypothesis formation, experimentation, and analysis.

Question 12

Which equation represents the exponential growth of bacteria under ideal conditions?

Accepted Answer

$N = N_0 e^{rt}$

Question 13

Which of the following is a real-world example of bioremediation?

Accepted Answer

Using microbes to degrade petroleum oil spills into $CO_2$

Question 14

Which of the following is true about viruses and prions?

Accepted Answer

They are noncellular and nonliving.

Question 15

Which site in the human body harbors the most diverse normal microbiota?

Accepted Answer

The intestines

Question 16

Which of the following is an example of microbial antagonism?

Accepted Answer

Normal microbiota competing with potential pathogens to prevent overgrowth.

Question 17

Which of the following statements about transient microbiota is correct?

Accepted Answer

They are temporarily acquired and can be removed by proper hygiene.

Question 18

Which scientist is known for using carbolic acid (phenol) to sterilize surgical instruments and wounds?

Accepted Answer

Joseph Lister

Question 19

Which of the following is a correct example of binomial nomenclature?

Accepted Answer

Staphylococcus aureus

Question 20

Which of the following best describes commensalism in host-microbe interactions?

Accepted Answer

Microbe benefits; host is neither harmed nor helped.

Introduction to Microbiology: Basic Principles and History

Study Guide - Practice Questions