Question 1

Which of the following is NOT a characteristic shared by all living things according to the study materials?

Accepted Answer

Ability to metabolize energy independently

Question 2

A scientist isolates a microorganism that has a thick peptidoglycan layer and stains purple with the Gram stain. Which of the following is most likely true about this organism?

Accepted Answer

It is a Gram-positive bacterium.

Question 3

Which component of the Gram-negative bacterial cell wall is responsible for causing fever and shock in humans?

Accepted Answer

Lipid A (part of LPS)

Question 4

A patient develops a severe inflammatory response after a Gram-negative bacterial infection. Which molecule is most likely responsible for this reaction, and what is its mechanism?

Accepted Answer

Lipid A; released as an endotoxin when bacteria die or divide

Question 5

Which of the following best describes the function of the bacterial flagellum?

Accepted Answer

Motility, allowing movement toward nutrients or away from toxins

Question 6

A microbiologist observes a bacterial structure that is short, numerous, and hairlike, aiding in attachment to surfaces. What is this structure and its primary function?

Accepted Answer

Fimbriae; attachment to surfaces and biofilm formation

Question 7

Which of the following statements about viruses is TRUE based on the study materials?

Accepted Answer

Viruses require host cell machinery to reproduce.

Question 8

Which evidence supports the endosymbiotic theory for the origin of mitochondria and chloroplasts?

Accepted Answer

Division by binary fission

Question 9

A hospital-acquired infection is traced to a biofilm on a catheter. Which property of biofilms most likely contributed to the persistence of this infection?

Accepted Answer

Biofilms protect microbes from antibiotics and immune system defenses.

Question 10

Which of the following best explains why Gram-negative bacteria are generally more resistant to antibiotics than Gram-positive bacteria?

Accepted Answer

They possess an outer membrane that acts as a barrier to many antibiotics.

Question 11

A researcher stains a bacterial sample and observes pink/red cells under the microscope. Which of the following is the most likely explanation?

Accepted Answer

The bacteria are Gram-negative and have a thin peptidoglycan layer.

Question 12

Which of the following is a function of the bacterial capsule?

Accepted Answer

Protection against phagocytosis

Question 13

Which of the following best describes the structure and function of pili in bacteria?

Accepted Answer

Longer, fewer, used for DNA transfer (conjugation)

Question 14

A Gram-negative bacterium is exposed to an antibiotic that targets peptidoglycan synthesis. Which structure may help it survive better than a Gram-positive bacterium?

Accepted Answer

Outer membrane containing LPS

Question 15

Which of the following is NOT a function of the glycocalyx in bacteria?

Accepted Answer

Motility

Question 16

Which of the following best explains why cells within a biofilm can communicate with each other?

Accepted Answer

They use quorum sensing to coordinate activities.

Question 17

Which of the following is a correct statement about the structure of the bacterial flagellum?

Accepted Answer

It is composed of a filament, hook, and basal body.

Question 18

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

Accepted Answer

Dental plaque on teeth

Question 19

Which of the following is NOT evidence supporting the endosymbiotic theory?

Accepted Answer

Mitochondria and chloroplasts have a single membrane.

Question 20

Which of the following best describes the role of Lipid A in Gram-negative bacteria?

Accepted Answer

It acts as an endotoxin, causing fever and shock.

Chapter 3: Fundamental Concepts in Microbiology – Cell Structure, Function, and Microbial Communities

Study Guide - Practice Questions

Study Guide - Flashcards