D311 OA Exam – WGU Microbiology Objective
Assessment (2026/2027) Actual Questions & Study
Guide | Guarantee Pass
200 QUESTIONS
TABLE OF CONTENTS
# TOPIC
1 Microbial Structure & Function
2 Microbial Growth & Metabolism
3 Microbial Genetics
4 Control of Microorganisms
5 Immunology
6 Host-Pathogen Interactions
7 Bacteriology
8 Virology
9 Mycology & Parasitology
10 Laboratory Diagnosis
11 Epidemiology & Infection Control
,Q1
Which organelle is responsible for ATP production in eukaryotic cells?
A) Nucleus
B) Mitochondrion CORRECT
C) Ribosome
D) Golgi apparatus
Rationale
Mitochondria perform oxidative phosphorylation to produce ATP via cellular respiration.
Q2
Which of the following is a prokaryotic organism?
A) Fungi
B) Bacteria CORRECT
C) Plant cell
D) Animal cell
Rationale
Bacteria lack a nucleus and membrane-bound organelles, defining them as prokaryotes.
Q3
The plasma membrane is primarily composed of:
A) Cellulose and chitin
B) Phospholipids and proteins CORRECT
C) Nucleic acids and amino acids
D) Glycogen and starch
Rationale
The phospholipid bilayer with embedded proteins forms the basic structure of cell membranes.
2
,Q4
Which of the following is NOT a function of the smooth endoplasmic reticulum?
A) Lipid synthesis
B) Detoxification of drugs
C) Calcium storage
D) Protein synthesis CORRECT
Rationale
Protein synthesis is primarily performed by ribosomes and the rough ER. Smooth ER synthesizes lipids
and detoxifies.
Q5
Enzymes are biological catalysts that:
A) Increase the activation energy of a reaction
B) Lower the activation energy of a reaction CORRECT
C) Are consumed in the reaction
D) Change the equilibrium constant
Rationale
Enzymes lower activation energy, speeding up reactions without being consumed.
Q6
Which of the following is a polysaccharide used for energy storage in animals?
A) Cellulose
B) Starch
C) Glycogen CORRECT
D) Chitin
Rationale
Glycogen is the primary energy storage polysaccharide in animals, stored in liver and muscle.
3
, Q7
DNA replication is described as semiconservative because:
A) Only one strand is replicated
B) Each daughter molecule contains one old strand and one new strand CORRECT
C) The entire molecule is copied from a template
D) It occurs in the cytoplasm
Rationale
In semiconservative replication, each parental strand serves as a template for a new strand.
Q8
In cellular respiration, the majority of ATP is produced during:
A) Glycolysis
B) The Krebs cycle
C) Oxidative phosphorylation CORRECT
D) Fermentation
Rationale
The electron transport chain and chemiosmosis generate approximately 34 ATP per glucose molecule.
Q9
Which nitrogenous base is found in RNA but NOT in DNA?
A) Adenine
B) Guanine
C) Cytosine
D) Uracil CORRECT
4
Assessment (2026/2027) Actual Questions & Study
Guide | Guarantee Pass
200 QUESTIONS
TABLE OF CONTENTS
# TOPIC
1 Microbial Structure & Function
2 Microbial Growth & Metabolism
3 Microbial Genetics
4 Control of Microorganisms
5 Immunology
6 Host-Pathogen Interactions
7 Bacteriology
8 Virology
9 Mycology & Parasitology
10 Laboratory Diagnosis
11 Epidemiology & Infection Control
,Q1
Which organelle is responsible for ATP production in eukaryotic cells?
A) Nucleus
B) Mitochondrion CORRECT
C) Ribosome
D) Golgi apparatus
Rationale
Mitochondria perform oxidative phosphorylation to produce ATP via cellular respiration.
Q2
Which of the following is a prokaryotic organism?
A) Fungi
B) Bacteria CORRECT
C) Plant cell
D) Animal cell
Rationale
Bacteria lack a nucleus and membrane-bound organelles, defining them as prokaryotes.
Q3
The plasma membrane is primarily composed of:
A) Cellulose and chitin
B) Phospholipids and proteins CORRECT
C) Nucleic acids and amino acids
D) Glycogen and starch
Rationale
The phospholipid bilayer with embedded proteins forms the basic structure of cell membranes.
2
,Q4
Which of the following is NOT a function of the smooth endoplasmic reticulum?
A) Lipid synthesis
B) Detoxification of drugs
C) Calcium storage
D) Protein synthesis CORRECT
Rationale
Protein synthesis is primarily performed by ribosomes and the rough ER. Smooth ER synthesizes lipids
and detoxifies.
Q5
Enzymes are biological catalysts that:
A) Increase the activation energy of a reaction
B) Lower the activation energy of a reaction CORRECT
C) Are consumed in the reaction
D) Change the equilibrium constant
Rationale
Enzymes lower activation energy, speeding up reactions without being consumed.
Q6
Which of the following is a polysaccharide used for energy storage in animals?
A) Cellulose
B) Starch
C) Glycogen CORRECT
D) Chitin
Rationale
Glycogen is the primary energy storage polysaccharide in animals, stored in liver and muscle.
3
, Q7
DNA replication is described as semiconservative because:
A) Only one strand is replicated
B) Each daughter molecule contains one old strand and one new strand CORRECT
C) The entire molecule is copied from a template
D) It occurs in the cytoplasm
Rationale
In semiconservative replication, each parental strand serves as a template for a new strand.
Q8
In cellular respiration, the majority of ATP is produced during:
A) Glycolysis
B) The Krebs cycle
C) Oxidative phosphorylation CORRECT
D) Fermentation
Rationale
The electron transport chain and chemiosmosis generate approximately 34 ATP per glucose molecule.
Q9
Which nitrogenous base is found in RNA but NOT in DNA?
A) Adenine
B) Guanine
C) Cytosine
D) Uracil CORRECT
4
