1. Which bacterium causes syphilis?
A. Treponema pallidum
B. Neisseria gonorrhoeae
C. Chlamydia trachomatis
D. Haemophilus ducreyi
Answer: A. Treponema pallidum
Rationale: Syphilis is caused by the spirochete bacterium
Treponema pallidum.
2. Which organism is a common cause of tuberculosis?
A. Mycobacterium tuberculosis
B. Streptococcus pneumoniae
C. Haemophilus influenzae
D. Bordetella pertussis
Answer: A. Mycobacterium tuberculosis
Rationale: Mycobacterium tuberculosis causes tuberculosis and is
transmitted via respiratory droplets.
3. What is the role of macrophages in the immune system?
A. Producing antibodies
,B. Presenting antigens and phagocytosing pathogens
C. Destroying infected host cells
D. Neutralizing toxins
Answer: B. Presenting antigens and phagocytosing pathogens
Rationale: Macrophages engulf pathogens, present antigens to T
cells, and initiate adaptive immune responses.
4. Which microorganism is a common cause of urinary tract
infections (UTIs)?
A. Staphylococcus epidermidis
B. Escherichia coli
C. Bacillus subtilis
D. Streptococcus pneumoniae
Answer: B. Escherichia coli
Rationale: E. coli is the leading cause of UTIs due to its ability to
adhere to the urinary epithelium.
5. Which microorganism causes whooping cough?
A. Haemophilus influenzae
B. Bordetella pertussis
C. Corynebacterium diphtheriae
D. Legionella pneumophila
, Answer: B. Bordetella pertussis
Rationale: Bordetella pertussis infects the respiratory tract and
produces toxins causing the characteristic cough.
6. Which bacteria are known to form endospores?
A. Escherichia coli
B. Bacillus and Clostridium species
C. Staphylococcus aureus
D. Pseudomonas aeruginosa
Answer: B. Bacillus and Clostridium species
Rationale: Endospore formation is a survival mechanism used by
Bacillus and Clostridium species in harsh conditions.
7. Which bacterial structure protects against phagocytosis?
A. Capsule
B. Flagella
C. Pili
D. Ribosome
Answer: A. Capsule
Rationale: The capsule prevents phagocytosis by masking
bacterial antigens and preventing immune cell recognition.
A. Treponema pallidum
B. Neisseria gonorrhoeae
C. Chlamydia trachomatis
D. Haemophilus ducreyi
Answer: A. Treponema pallidum
Rationale: Syphilis is caused by the spirochete bacterium
Treponema pallidum.
2. Which organism is a common cause of tuberculosis?
A. Mycobacterium tuberculosis
B. Streptococcus pneumoniae
C. Haemophilus influenzae
D. Bordetella pertussis
Answer: A. Mycobacterium tuberculosis
Rationale: Mycobacterium tuberculosis causes tuberculosis and is
transmitted via respiratory droplets.
3. What is the role of macrophages in the immune system?
A. Producing antibodies
,B. Presenting antigens and phagocytosing pathogens
C. Destroying infected host cells
D. Neutralizing toxins
Answer: B. Presenting antigens and phagocytosing pathogens
Rationale: Macrophages engulf pathogens, present antigens to T
cells, and initiate adaptive immune responses.
4. Which microorganism is a common cause of urinary tract
infections (UTIs)?
A. Staphylococcus epidermidis
B. Escherichia coli
C. Bacillus subtilis
D. Streptococcus pneumoniae
Answer: B. Escherichia coli
Rationale: E. coli is the leading cause of UTIs due to its ability to
adhere to the urinary epithelium.
5. Which microorganism causes whooping cough?
A. Haemophilus influenzae
B. Bordetella pertussis
C. Corynebacterium diphtheriae
D. Legionella pneumophila
, Answer: B. Bordetella pertussis
Rationale: Bordetella pertussis infects the respiratory tract and
produces toxins causing the characteristic cough.
6. Which bacteria are known to form endospores?
A. Escherichia coli
B. Bacillus and Clostridium species
C. Staphylococcus aureus
D. Pseudomonas aeruginosa
Answer: B. Bacillus and Clostridium species
Rationale: Endospore formation is a survival mechanism used by
Bacillus and Clostridium species in harsh conditions.
7. Which bacterial structure protects against phagocytosis?
A. Capsule
B. Flagella
C. Pili
D. Ribosome
Answer: A. Capsule
Rationale: The capsule prevents phagocytosis by masking
bacterial antigens and preventing immune cell recognition.
