Page 1 of 166
“ MEDICAL MICROBIOLOGY MCQS EXAM “ NEWEST
UPDATED EXAM 2025 – 2026 SOLVED QUESTIONS &
ANSWERS VERIFIED 100% GRADED A+ (LATEST
VERSION)
Medical Microbiology Exam
Clostridium difficile (C. diff) is able to resist treatment and survive harsh
environmental conditions due to which of the following:
A. plasmids
B. quorum sensing
C. sporulation
D. peptidoglycan wall
C) sporulation
At what phase are phage proteins made in the generalized bacteriophage
cycle?
A. Penetration
B. Maturation
C. Biosynthesis
D. Attachment
C) biosynthesis
Why is the capsule of a microbe important?
The capsule is important because it protects the microbes from phagocytosis by the
macrophages.
Which of the following is required for all viruses to replicate?
a.) The virus being able to attach to any cell receptor
b.) Having the ability to independently synthesize proteins
, Page 2 of 166
c.) Being able to recognize and attach to a permissive host cell
d.) Having both RNA and DNA genomes
C) being able to recognize and attach to a permissive host cell
Which is not a benefit from microbes?
a) causes many deaths worldwide
b) medicines such as insulin
c) microbes recycle nutrients
A) causes many deaths worldwide
What are bacteriophages?
A. infect animals; envelope
B. infect animals; no envelope
C. infect bacteria; DNA viruses; no envelope
D. infect fungi; envelope
C) infect bacteria; DNA viruses; no envelope
Which of the following is the best explanation for why C. difficile infections
recur even after antibiotic treatment.
A. The bacterium forms biofilms that stop antibiotics from working
B. The bacterium releases endospores that are resistant to antibiotics
C. The bacterium produces a capsule to block antibiotics from entering
D. The bacteria is resistant to antibiotic treatment
B) the bacterium releases endospores that are resistant to antibiotics
Which feature is found in all viruses regardless of their type?
A. Ribosomes to make viral proteins.
B. A nucleus
C. A lipid envelope surrounding the virus.
D. A protein coat enclosing genetic material.
D. A protein coat enclosing genetic material
Which experiment led to the understanding that microbes cannot form from
non-living things, even in the presence of O2?
A. Aristotle's spontaneous generation experiment
B. Francesco Redi's cork-sealed container experiment
C. Lazzaro Spallanzani's boiling-sealing experiment
D. Louis Pasteur's swan-neck flask experiment
D) Louis Pasteur's swan- neck flask experiment
, Page 3 of 166
Which of the following best describes biosynthesis in the generalized
bacteriophage cycle?
A) New phage particles are assembled
B) Cell lunes and releases the newly made phases.
C) Phage DNA replicates and the phage proteins are made. Phage attaches to
the surface of the host
D) Phage attaches to the surface of the host
C) phage DNA replicates and the phage proteins are made. Phage attaches to the
surface of the host
Which of the following is NOT a reason why Gram-negative bacteria are harder
to treat?
A. They have an additional outer membrane
B. They are prone to developing antibiotic resistance
C. They lack a lipopolysaccharide (LPS) structure
D. They have a thin peptidoglycan wall (cell wall)
C) they lack a lipopolysaccharide (LPS) structure
A high dose of antibiotic kills almost all bacteria in a culture. A tiny fraction
survives. After the antibiotic is removed, those survivors grow normally and
are just as sensitive to the antibiotic as before. No gene changes are found.
What best explains the survivors?
a) A new resistance mutation
b) Temporary persister cells that were dormant
c) Formation of endospores
d) Gained a resistance plasmid
e) Protection by a biofilm in the liquid culture
B) temporary persistent cells that were dormant
Who first described the presence of "small" animals under the microscope?
Antony Van Leeuwenhoek
Found on the outer membrane of gram-negative bacteria— can act as an
endotoxin:
Lippolysacharide
Which of the following does not describe a bacteria shape?
A. Vibrio
B. L-shaped
C. Cocci
D. Spiral
B. L-shaped
Which of the following is a type of fungal microorganism?
A. Bacterium
B. Protozoan
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C. Alga
D. Yeast
D. Yeast
Who is credited of developing the systematic approach to identify the caste of
disease?
Koch
Now debunked— what is the process by which living things originate from
non-living things?
Spontaneous generation
Which of the following is NOT a characteristic of a virus?
A. Acellular pathogens
B. Host cell specificity
C. Simple structure
D. Membrane- bound organelles
E. Change over time
D. Membrane- bound organelles
The nucleic acid of a virus is likely to be found where?
Capsid
Which of the following is NOT true about the viral life cycle?
A. Host recognition and attachment
B. Exit and transmission
C. Replicate independently
D. Assembly of virions
C. Replicate independently
Which of the following would be most suited to be used for treating a patient
with drug- resistant septic infection?
1. HIV
2. Phage therapy
3. SARS-Cov-2
4. Homosapians
2. Phage therapy
Select the best choice that matches the following statement;
"Phage DNA is replicated and proteins are made"
A. Lysis
B. Maturation
C. Penetration
D. Biosynthesis
E. Attachment
D. Biosynthesis
Which of the following examples the survival of a microbe when it encounters
an environment unfavorable for growth?
“ MEDICAL MICROBIOLOGY MCQS EXAM “ NEWEST
UPDATED EXAM 2025 – 2026 SOLVED QUESTIONS &
ANSWERS VERIFIED 100% GRADED A+ (LATEST
VERSION)
Medical Microbiology Exam
Clostridium difficile (C. diff) is able to resist treatment and survive harsh
environmental conditions due to which of the following:
A. plasmids
B. quorum sensing
C. sporulation
D. peptidoglycan wall
C) sporulation
At what phase are phage proteins made in the generalized bacteriophage
cycle?
A. Penetration
B. Maturation
C. Biosynthesis
D. Attachment
C) biosynthesis
Why is the capsule of a microbe important?
The capsule is important because it protects the microbes from phagocytosis by the
macrophages.
Which of the following is required for all viruses to replicate?
a.) The virus being able to attach to any cell receptor
b.) Having the ability to independently synthesize proteins
, Page 2 of 166
c.) Being able to recognize and attach to a permissive host cell
d.) Having both RNA and DNA genomes
C) being able to recognize and attach to a permissive host cell
Which is not a benefit from microbes?
a) causes many deaths worldwide
b) medicines such as insulin
c) microbes recycle nutrients
A) causes many deaths worldwide
What are bacteriophages?
A. infect animals; envelope
B. infect animals; no envelope
C. infect bacteria; DNA viruses; no envelope
D. infect fungi; envelope
C) infect bacteria; DNA viruses; no envelope
Which of the following is the best explanation for why C. difficile infections
recur even after antibiotic treatment.
A. The bacterium forms biofilms that stop antibiotics from working
B. The bacterium releases endospores that are resistant to antibiotics
C. The bacterium produces a capsule to block antibiotics from entering
D. The bacteria is resistant to antibiotic treatment
B) the bacterium releases endospores that are resistant to antibiotics
Which feature is found in all viruses regardless of their type?
A. Ribosomes to make viral proteins.
B. A nucleus
C. A lipid envelope surrounding the virus.
D. A protein coat enclosing genetic material.
D. A protein coat enclosing genetic material
Which experiment led to the understanding that microbes cannot form from
non-living things, even in the presence of O2?
A. Aristotle's spontaneous generation experiment
B. Francesco Redi's cork-sealed container experiment
C. Lazzaro Spallanzani's boiling-sealing experiment
D. Louis Pasteur's swan-neck flask experiment
D) Louis Pasteur's swan- neck flask experiment
, Page 3 of 166
Which of the following best describes biosynthesis in the generalized
bacteriophage cycle?
A) New phage particles are assembled
B) Cell lunes and releases the newly made phases.
C) Phage DNA replicates and the phage proteins are made. Phage attaches to
the surface of the host
D) Phage attaches to the surface of the host
C) phage DNA replicates and the phage proteins are made. Phage attaches to the
surface of the host
Which of the following is NOT a reason why Gram-negative bacteria are harder
to treat?
A. They have an additional outer membrane
B. They are prone to developing antibiotic resistance
C. They lack a lipopolysaccharide (LPS) structure
D. They have a thin peptidoglycan wall (cell wall)
C) they lack a lipopolysaccharide (LPS) structure
A high dose of antibiotic kills almost all bacteria in a culture. A tiny fraction
survives. After the antibiotic is removed, those survivors grow normally and
are just as sensitive to the antibiotic as before. No gene changes are found.
What best explains the survivors?
a) A new resistance mutation
b) Temporary persister cells that were dormant
c) Formation of endospores
d) Gained a resistance plasmid
e) Protection by a biofilm in the liquid culture
B) temporary persistent cells that were dormant
Who first described the presence of "small" animals under the microscope?
Antony Van Leeuwenhoek
Found on the outer membrane of gram-negative bacteria— can act as an
endotoxin:
Lippolysacharide
Which of the following does not describe a bacteria shape?
A. Vibrio
B. L-shaped
C. Cocci
D. Spiral
B. L-shaped
Which of the following is a type of fungal microorganism?
A. Bacterium
B. Protozoan
, Page 4 of 166
C. Alga
D. Yeast
D. Yeast
Who is credited of developing the systematic approach to identify the caste of
disease?
Koch
Now debunked— what is the process by which living things originate from
non-living things?
Spontaneous generation
Which of the following is NOT a characteristic of a virus?
A. Acellular pathogens
B. Host cell specificity
C. Simple structure
D. Membrane- bound organelles
E. Change over time
D. Membrane- bound organelles
The nucleic acid of a virus is likely to be found where?
Capsid
Which of the following is NOT true about the viral life cycle?
A. Host recognition and attachment
B. Exit and transmission
C. Replicate independently
D. Assembly of virions
C. Replicate independently
Which of the following would be most suited to be used for treating a patient
with drug- resistant septic infection?
1. HIV
2. Phage therapy
3. SARS-Cov-2
4. Homosapians
2. Phage therapy
Select the best choice that matches the following statement;
"Phage DNA is replicated and proteins are made"
A. Lysis
B. Maturation
C. Penetration
D. Biosynthesis
E. Attachment
D. Biosynthesis
Which of the following examples the survival of a microbe when it encounters
an environment unfavorable for growth?
