P O RTA G E L E A R N I N G
Microbiology
BIOL 271 — Microbiology
Academic Year: 2026/2027
Comprehensive Question Bank
Module 1 Test
Question 1
Can viruses be classified as either prokaryotic or eukaryotic?
A. Yes - they are prokaryotic
B. Yes - they are eukaryotic
C. Neither - Viruses are not considered living and do not replicate on their own
D. They can be classified as either depending on the type
CORRECT ANSWER:
C. Neither - Viruses are not considered living and do not replicate on their
own
RATIONALE:
Viruses are not classified as either prokaryotic or eukaryotic because they are not
considered living organisms. They are acellular and cannot replicate on their own,
requiring a host cell for reproduction.
, Question 2
A molecule capable of causing disease is known as a:
A. Microbe
B. Pathogen
C. Prion
D. Virus
CORRECT ANSWER: B. Pathogen
RATIONALE:
A pathogen is any molecule or organism capable of causing disease. This includes
bacteria, viruses, fungi, parasites, and prions that can infect a host and cause illness.
Question 3
What is an epidemic disease?
A. Frequency of disease increases above the expected number in a specific area and
time frame
B. Disease always present at a baseline in a particular region
C. Exponential infections covering multiple countries
D. Dispersed cases with rare occurrence
CORRECT ANSWER:
A. Frequency of disease increases above the expected number in a specific
area and time frame
RATIONALE:
An epidemic occurs when the frequency of a disease increases above the expected
number in a specific area and time frame. Examples include Lyme disease, West Nile
virus, and polio outbreaks.
, Question 4
Cell wall components of BACTERIAL cells are made of:
A. Peptidoglycan
B. S-layer proteins
C. Cellulose
D. Chitin
CORRECT ANSWER: A. Peptidoglycan
RATIONALE:
Bacterial cell walls are composed of peptidoglycan, a polymer consisting of sugars and
amino acids that forms a mesh-like layer. This provides structural support and protects
the cell from osmotic lysis.
, Question 5
What is a base pair in a nucleotide and how is it formed?
A. Bonding of two nucleotides from opposite DNA strands formed via hydrogen
bonds
B. Bonding of two nucleotides from the same DNA strand
C. Bonding of nucleotides to amino acids
D. Bonding of nucleotides to lipids
CORRECT ANSWER:
A. Bonding of two nucleotides from opposite DNA strands formed via
hydrogen bonds
RATIONALE:
A base pair is formed when two nucleotides from opposite DNA strands bond together
through hydrogen bonds. The specific base pairing (A-T and C-G) is essential for the
double helix structure of DNA.
Microbiology
BIOL 271 — Microbiology
Academic Year: 2026/2027
Comprehensive Question Bank
Module 1 Test
Question 1
Can viruses be classified as either prokaryotic or eukaryotic?
A. Yes - they are prokaryotic
B. Yes - they are eukaryotic
C. Neither - Viruses are not considered living and do not replicate on their own
D. They can be classified as either depending on the type
CORRECT ANSWER:
C. Neither - Viruses are not considered living and do not replicate on their
own
RATIONALE:
Viruses are not classified as either prokaryotic or eukaryotic because they are not
considered living organisms. They are acellular and cannot replicate on their own,
requiring a host cell for reproduction.
, Question 2
A molecule capable of causing disease is known as a:
A. Microbe
B. Pathogen
C. Prion
D. Virus
CORRECT ANSWER: B. Pathogen
RATIONALE:
A pathogen is any molecule or organism capable of causing disease. This includes
bacteria, viruses, fungi, parasites, and prions that can infect a host and cause illness.
Question 3
What is an epidemic disease?
A. Frequency of disease increases above the expected number in a specific area and
time frame
B. Disease always present at a baseline in a particular region
C. Exponential infections covering multiple countries
D. Dispersed cases with rare occurrence
CORRECT ANSWER:
A. Frequency of disease increases above the expected number in a specific
area and time frame
RATIONALE:
An epidemic occurs when the frequency of a disease increases above the expected
number in a specific area and time frame. Examples include Lyme disease, West Nile
virus, and polio outbreaks.
, Question 4
Cell wall components of BACTERIAL cells are made of:
A. Peptidoglycan
B. S-layer proteins
C. Cellulose
D. Chitin
CORRECT ANSWER: A. Peptidoglycan
RATIONALE:
Bacterial cell walls are composed of peptidoglycan, a polymer consisting of sugars and
amino acids that forms a mesh-like layer. This provides structural support and protects
the cell from osmotic lysis.
, Question 5
What is a base pair in a nucleotide and how is it formed?
A. Bonding of two nucleotides from opposite DNA strands formed via hydrogen
bonds
B. Bonding of two nucleotides from the same DNA strand
C. Bonding of nucleotides to amino acids
D. Bonding of nucleotides to lipids
CORRECT ANSWER:
A. Bonding of two nucleotides from opposite DNA strands formed via
hydrogen bonds
RATIONALE:
A base pair is formed when two nucleotides from opposite DNA strands bond together
through hydrogen bonds. The specific base pairing (A-T and C-G) is essential for the
double helix structure of DNA.
