WGU D311 Microbiology OA Definitions, Reviews &
Study Guide (2026/2027) | Guarantee Pass
220 QUESTIONS
TABLE OF CONTENTS
# TOPIC
1 Microbial Structure & Classification
2 Microbial Growth & Metabolism
3 Microbial Genetics
4 Virology
5 Mycology
6 Parasitology
7 Immunology & Host Defenses
8 Antimicrobials
9 Lab Techniques
10 Epidemiology & Infection Control
,Q1
Which of the following is a prokaryotic organism?
A) Fungi
B) Bacteria CORRECT
C) Protozoa
D) Algae
Rationale
Bacteria are prokaryotes (no nucleus); fungi, protozoa, and algae are eukaryotes.
Q2
The cell wall of most bacteria contains:
A) Cellulose
B) Peptidoglycan CORRECT
C) Chitin
D) Cholesterol
Rationale
Peptidoglycan is the major component of bacterial cell walls, target of penicillin.
Q3
Which structure allows bacteria to attach to surfaces?
A) Flagella
B) Pili (fimbriae) CORRECT
C) Capsule
D) Endospore
Rationale
Pili mediate adhesion to host cells; flagella are for motility.
2
,Q4
Gram-positive bacteria appear _____ under the microscope.
A) Pink/red
B) Purple/blue CORRECT
C) Green
D) Colorless
Rationale
Gram-positive retain crystal violet-iodine complex, appearing purple.
Q5
Which of the following is an obligate intracellular pathogen?
A) Escherichia coli
B) Chlamydia trachomatis CORRECT
C) Staphylococcus aureus
D) Pseudomonas aeruginosa
Rationale
Chlamydia cannot synthesize ATP and must replicate inside host cells.
Q6
The bacterial growth curve phase with rapid cell division is:
A) Lag phase
B) Log phase CORRECT
C) Stationary phase
D) Death phase
Rationale
Log (exponential) phase has maximal growth rate; cells are most susceptible to antibiotics.
3
, Q7
Which of the following is a strict anaerobe?
A) E. coli
B) Clostridium difficile CORRECT
C) Staphylococcus aureus
D) Pseudomonas aeruginosa
Rationale
Clostridium species are obligate anaerobes, killed by oxygen.
Q8
The transfer of DNA via a bacteriophage is called:
A) Transformation
B) Transduction CORRECT
C) Conjugation
D) Transposition
Rationale
Transduction uses a virus to move bacterial DNA between cells.
Q9
Which of the following is a DNA virus?
A) Influenza
B) HIV
C) Herpes simplex CORRECT
D) Polio
Rationale
Herpesviruses are DNA viruses; influenza, HIV, and polio are RNA viruses.
4
Study Guide (2026/2027) | Guarantee Pass
220 QUESTIONS
TABLE OF CONTENTS
# TOPIC
1 Microbial Structure & Classification
2 Microbial Growth & Metabolism
3 Microbial Genetics
4 Virology
5 Mycology
6 Parasitology
7 Immunology & Host Defenses
8 Antimicrobials
9 Lab Techniques
10 Epidemiology & Infection Control
,Q1
Which of the following is a prokaryotic organism?
A) Fungi
B) Bacteria CORRECT
C) Protozoa
D) Algae
Rationale
Bacteria are prokaryotes (no nucleus); fungi, protozoa, and algae are eukaryotes.
Q2
The cell wall of most bacteria contains:
A) Cellulose
B) Peptidoglycan CORRECT
C) Chitin
D) Cholesterol
Rationale
Peptidoglycan is the major component of bacterial cell walls, target of penicillin.
Q3
Which structure allows bacteria to attach to surfaces?
A) Flagella
B) Pili (fimbriae) CORRECT
C) Capsule
D) Endospore
Rationale
Pili mediate adhesion to host cells; flagella are for motility.
2
,Q4
Gram-positive bacteria appear _____ under the microscope.
A) Pink/red
B) Purple/blue CORRECT
C) Green
D) Colorless
Rationale
Gram-positive retain crystal violet-iodine complex, appearing purple.
Q5
Which of the following is an obligate intracellular pathogen?
A) Escherichia coli
B) Chlamydia trachomatis CORRECT
C) Staphylococcus aureus
D) Pseudomonas aeruginosa
Rationale
Chlamydia cannot synthesize ATP and must replicate inside host cells.
Q6
The bacterial growth curve phase with rapid cell division is:
A) Lag phase
B) Log phase CORRECT
C) Stationary phase
D) Death phase
Rationale
Log (exponential) phase has maximal growth rate; cells are most susceptible to antibiotics.
3
, Q7
Which of the following is a strict anaerobe?
A) E. coli
B) Clostridium difficile CORRECT
C) Staphylococcus aureus
D) Pseudomonas aeruginosa
Rationale
Clostridium species are obligate anaerobes, killed by oxygen.
Q8
The transfer of DNA via a bacteriophage is called:
A) Transformation
B) Transduction CORRECT
C) Conjugation
D) Transposition
Rationale
Transduction uses a virus to move bacterial DNA between cells.
Q9
Which of the following is a DNA virus?
A) Influenza
B) HIV
C) Herpes simplex CORRECT
D) Polio
Rationale
Herpesviruses are DNA viruses; influenza, HIV, and polio are RNA viruses.
4
