Microbiology UTA 2460 - Exam 2 Test
Bank (2026/2027), Questions & Answers
(Verified Answers) With Detailed
Rationales || Complete A+ Guide - UTA
1. The __ stain is used to stain and differentiate Mycobacterium and Nocardia from other
bacteria.
A) Gram stain
B) Acid-fast stain
C) Endospore stain
D) Capsule stain
E) Flagella stain
Answer: B) Acid-fast stain
Rationale: The acid-fast stain is used to identify bacteria with a waxy cell wall containing
mycolic acids, characteristic of Mycobacterium and Nocardia.
2. Lipopolysaccharide (LPS) is an important cell wall component of:
A) Gram-positive bacteria
B) Gram-negative bacteria
C) Fungi
D) Archaea
E) Protozoa
Answer: B) Gram-negative bacteria
Rationale: LPS is a major component of the outer membrane found in gram-negative bacteria.
It acts as an endotoxin and is a key antigen.
3. An irregular cluster of spherical cells is termed __ while a chain of rod-shaped cells
would be called a __.
A) Staphylococcus, streptobacillus
B) Streptococcus, staphylobacillus
C) Sarcina, streptobacillus
D) Staphylobacillus, streptococcus
E) Streptobacillus, staphylococcus
Answer: A) Staphylococcus, streptobacillus
Rationale: "Staphylo-" refers to a grape-like cluster arrangement, and "strepto-" refers to a
chain arrangement. "-coccus" denotes spherical cells, while "-bacillus" denotes rod-shaped cells.
,4. The bacterial flagellum has 3 parts in the order from cytoplasm to external
environment. They are:
A) Filament, hook, basal body
B) Basal body, filament, hook
C) Hook, basal body, filament
D) Basal body, hook, and filament
E) Filament, basal body, hook
Answer: D) Basal body, hook, and filament
Rationale: The flagellum structure is anchored in the cell envelope by the basal body. The hook
connects the basal body to the long, external filament.
5. Chitin is a chemical component of the cell walls of:
A) Bacteria
B) Fungi
C) Algae
D) Protozoa
E) Viruses
Answer: B) Fungi
Rationale: Chitin is a long-chain polymer that provides structural support in the cell walls of
fungi.
6. The long, thread-like branching cells of molds are called:
A) Hyphae
B) Mycelium
C) Yeast
D) Spores
E) Trophozoites
Answer: A) Hyphae
Rationale: Hyphae are the long, branching filamentous structures that make up the body
(mycelium) of a mold.
7. Spirochetes have a twisting and flexing locomotion due to appendages called:
A) Flagella
B) Periplasmic flagella (axial filaments)
C) Pili
D) Fimbriae
E) Pseudopodia
Answer: B) Periplasmic flagella (axial filaments)
Rationale: The corkscrew-like movement of spirochetes is due to axial filaments located in the
periplasmic space, not external flagella.
8. In eukaryotic cells, which of the following contains DNA?
A) Nucleus, chloroplast, and mitochondria
,B) Nucleus, ribosomes, and mitochondria
C) Chloroplast, mitochondria, and endoplasmic reticulum
D) Nucleus, plasma membrane, and ribosomes
E) All of the above
Answer: A) Nucleus, chloroplast, and mitochondria
Rationale: The nucleus is the primary site of genetic material. Mitochondria and chloroplasts
contain their own circular DNA.
9. A naked virus only has a:
A) Capsid and envelope
B) Nucleocapsid
C) Genome and envelope
D) Spikes and capsid
E) Capsid, spikes, and envelope
Answer: B) Nucleocapsid
Rationale: A naked virus consists only of a nucleocapsid (genome + capsid) without an
envelope.
Section 2: Viral Structure & Multiplication
10. The correct sequence of events in viral multiplication is:
A) Penetration, adsorption, uncoating, synthesis, assembly, release
B) Adsorption, penetration, uncoating, synthesis, assembly, release
C) Adsorption, uncoating, penetration, synthesis, assembly, release
D) Synthesis, adsorption, penetration, uncoating, assembly, release
E) Adsorption, penetration, synthesis, uncoating, assembly, release
Answer: B) Adsorption, penetration, uncoating, synthesis, assembly, release
Rationale: This is the standard lytic cycle order: the virus attaches (adsorption), enters
(penetration), removes its capsid (uncoating), uses the host to make new parts (synthesis), puts
them together (assembly), and is released.
11. What are the protein subunits that make up a viral capsid called?
A) Spikes
B) Capsomeres
C) Envelopes
D) Peplomers
E) Phages
Answer: B) Capsomeres
Rationale: Capsomeres are the individual protein building blocks that self-assemble to form the
capsid, which protects the viral genome.
, 12. What is the term for the activation of a prophage, causing it to exit the host
chromosome and enter the lytic cycle?
A) Transduction
B) Transformation
C) Induction
D) Conjugation
E) Lysogeny
Answer: C) Induction
Rationale: Induction is the switch from a latent lysogenic cycle to an active lytic cycle, often
triggered by environmental stress like UV light.
13. What are infectious, naked strands of RNA that affect plants called?
A) Prions
B) Virions
C) Viroids
D) Phages
E) Spikes
Answer: C) Viroids
Rationale: Viroids are subviral agents composed solely of circular RNA, lacking a protein capsid.
They are significant pathogens of plants.
14. What is a 20-sided viral capsid shape called?
A) Helical
B) Complex
C) Icosahedral
D) Filamentous
E) Spherical
Answer: C) Icosahedral
Rationale: An icosahedron is a geometric shape with 20 triangular faces and 12 vertices. Many
viruses use this highly stable structure for their capsid.
15. What is the term for a virus that can remain in a host for long periods before
reactivating?
A) Acute virus
B) Chronic latent virus
C) Persistent virus
D) Virulent virus
E) Prion
Answer: B) Chronic latent virus
Rationale: These viruses establish persistent infections where they are not actively replicating
but can reactivate later due to various triggers (e.g., herpesviruses).
Bank (2026/2027), Questions & Answers
(Verified Answers) With Detailed
Rationales || Complete A+ Guide - UTA
1. The __ stain is used to stain and differentiate Mycobacterium and Nocardia from other
bacteria.
A) Gram stain
B) Acid-fast stain
C) Endospore stain
D) Capsule stain
E) Flagella stain
Answer: B) Acid-fast stain
Rationale: The acid-fast stain is used to identify bacteria with a waxy cell wall containing
mycolic acids, characteristic of Mycobacterium and Nocardia.
2. Lipopolysaccharide (LPS) is an important cell wall component of:
A) Gram-positive bacteria
B) Gram-negative bacteria
C) Fungi
D) Archaea
E) Protozoa
Answer: B) Gram-negative bacteria
Rationale: LPS is a major component of the outer membrane found in gram-negative bacteria.
It acts as an endotoxin and is a key antigen.
3. An irregular cluster of spherical cells is termed __ while a chain of rod-shaped cells
would be called a __.
A) Staphylococcus, streptobacillus
B) Streptococcus, staphylobacillus
C) Sarcina, streptobacillus
D) Staphylobacillus, streptococcus
E) Streptobacillus, staphylococcus
Answer: A) Staphylococcus, streptobacillus
Rationale: "Staphylo-" refers to a grape-like cluster arrangement, and "strepto-" refers to a
chain arrangement. "-coccus" denotes spherical cells, while "-bacillus" denotes rod-shaped cells.
,4. The bacterial flagellum has 3 parts in the order from cytoplasm to external
environment. They are:
A) Filament, hook, basal body
B) Basal body, filament, hook
C) Hook, basal body, filament
D) Basal body, hook, and filament
E) Filament, basal body, hook
Answer: D) Basal body, hook, and filament
Rationale: The flagellum structure is anchored in the cell envelope by the basal body. The hook
connects the basal body to the long, external filament.
5. Chitin is a chemical component of the cell walls of:
A) Bacteria
B) Fungi
C) Algae
D) Protozoa
E) Viruses
Answer: B) Fungi
Rationale: Chitin is a long-chain polymer that provides structural support in the cell walls of
fungi.
6. The long, thread-like branching cells of molds are called:
A) Hyphae
B) Mycelium
C) Yeast
D) Spores
E) Trophozoites
Answer: A) Hyphae
Rationale: Hyphae are the long, branching filamentous structures that make up the body
(mycelium) of a mold.
7. Spirochetes have a twisting and flexing locomotion due to appendages called:
A) Flagella
B) Periplasmic flagella (axial filaments)
C) Pili
D) Fimbriae
E) Pseudopodia
Answer: B) Periplasmic flagella (axial filaments)
Rationale: The corkscrew-like movement of spirochetes is due to axial filaments located in the
periplasmic space, not external flagella.
8. In eukaryotic cells, which of the following contains DNA?
A) Nucleus, chloroplast, and mitochondria
,B) Nucleus, ribosomes, and mitochondria
C) Chloroplast, mitochondria, and endoplasmic reticulum
D) Nucleus, plasma membrane, and ribosomes
E) All of the above
Answer: A) Nucleus, chloroplast, and mitochondria
Rationale: The nucleus is the primary site of genetic material. Mitochondria and chloroplasts
contain their own circular DNA.
9. A naked virus only has a:
A) Capsid and envelope
B) Nucleocapsid
C) Genome and envelope
D) Spikes and capsid
E) Capsid, spikes, and envelope
Answer: B) Nucleocapsid
Rationale: A naked virus consists only of a nucleocapsid (genome + capsid) without an
envelope.
Section 2: Viral Structure & Multiplication
10. The correct sequence of events in viral multiplication is:
A) Penetration, adsorption, uncoating, synthesis, assembly, release
B) Adsorption, penetration, uncoating, synthesis, assembly, release
C) Adsorption, uncoating, penetration, synthesis, assembly, release
D) Synthesis, adsorption, penetration, uncoating, assembly, release
E) Adsorption, penetration, synthesis, uncoating, assembly, release
Answer: B) Adsorption, penetration, uncoating, synthesis, assembly, release
Rationale: This is the standard lytic cycle order: the virus attaches (adsorption), enters
(penetration), removes its capsid (uncoating), uses the host to make new parts (synthesis), puts
them together (assembly), and is released.
11. What are the protein subunits that make up a viral capsid called?
A) Spikes
B) Capsomeres
C) Envelopes
D) Peplomers
E) Phages
Answer: B) Capsomeres
Rationale: Capsomeres are the individual protein building blocks that self-assemble to form the
capsid, which protects the viral genome.
, 12. What is the term for the activation of a prophage, causing it to exit the host
chromosome and enter the lytic cycle?
A) Transduction
B) Transformation
C) Induction
D) Conjugation
E) Lysogeny
Answer: C) Induction
Rationale: Induction is the switch from a latent lysogenic cycle to an active lytic cycle, often
triggered by environmental stress like UV light.
13. What are infectious, naked strands of RNA that affect plants called?
A) Prions
B) Virions
C) Viroids
D) Phages
E) Spikes
Answer: C) Viroids
Rationale: Viroids are subviral agents composed solely of circular RNA, lacking a protein capsid.
They are significant pathogens of plants.
14. What is a 20-sided viral capsid shape called?
A) Helical
B) Complex
C) Icosahedral
D) Filamentous
E) Spherical
Answer: C) Icosahedral
Rationale: An icosahedron is a geometric shape with 20 triangular faces and 12 vertices. Many
viruses use this highly stable structure for their capsid.
15. What is the term for a virus that can remain in a host for long periods before
reactivating?
A) Acute virus
B) Chronic latent virus
C) Persistent virus
D) Virulent virus
E) Prion
Answer: B) Chronic latent virus
Rationale: These viruses establish persistent infections where they are not actively replicating
but can reactivate later due to various triggers (e.g., herpesviruses).
