PORTAGE LEARNING BIOD 171
FINAL EXAM LATEST
1. True or False. Clostridium tetani is an obligate aerobe, which is why deep puncture
wounds are particularly susceptible to infection.
False. Clostridium tetani is an obligate anaerobe. Deep puncture wounds create an
oxygen-free environment ideal for its growth.
2. Match the following diseases with their correct causative agent type (Bacterial,
Viral, or Fungal).
Disease Causative Agent Type
1. Tuberculosis A. Viral
2. Ringworm B. Bacterial
3. Varicella (Chickenpox) C. Fungal
•
1. Tuberculosis → B. Bacterial
•
2. Ringworm → C. Fungal
•
3. Varicella (Chickenpox) → A. Viral
/
, 3. True or False. Prions are infectious proteins that, unlike viruses, contain no genetic
material (DNA or RNA).
True. Prions are misfolded proteins that cause diseases like mad cow disease and
Creutzfeldt-Jakob disease. They contain no nucleic acids.
4. Describe the primary mechanism by which the neurotoxin produced
by Clostridium botulinum causes flaccid paralysis.
The botulinum toxin prevents the release of the neurotransmitter acetylcholine at
neuromuscular junctions. This blocks nerve signals to muscles, leading to flaccid (limp)
paralysis.
5. Why is Gram-positive bacteria generally more susceptible to penicillin than
Gram-negative bacteria?
Penicillin inhibits peptidoglycan synthesis. Gram-positive bacteria have a thick,
exposed layer of peptidoglycan in their cell wall. Gram-negative bacteria have a thin
peptidoglycan layer that is covered by an outer membrane, which acts as a barrier and
prevents penicillin from easily reaching its target.
6. The ____________ is a gelatinous layer that surrounds the cell wall of some
bacteria and contributes to biofilm formation and evasion of the host immune
system.
Glycocalyx (or capsule/slime layer)
7. True or False. You would expect to find 80S ribosomes in the cytoplasm of a
bacterial cell.
False. Bacterial cells are prokaryotes and contain 70S ribosomes. Eukaryotic cells (e.g.,
human, fungal, plant) contain 80S ribosomes.
8. Rank the following microorganisms from largest to smallest typical size:
• Yeast cell
• Influenza virus
• Staphylococcus bacterium
/
FINAL EXAM LATEST
1. True or False. Clostridium tetani is an obligate aerobe, which is why deep puncture
wounds are particularly susceptible to infection.
False. Clostridium tetani is an obligate anaerobe. Deep puncture wounds create an
oxygen-free environment ideal for its growth.
2. Match the following diseases with their correct causative agent type (Bacterial,
Viral, or Fungal).
Disease Causative Agent Type
1. Tuberculosis A. Viral
2. Ringworm B. Bacterial
3. Varicella (Chickenpox) C. Fungal
•
1. Tuberculosis → B. Bacterial
•
2. Ringworm → C. Fungal
•
3. Varicella (Chickenpox) → A. Viral
/
, 3. True or False. Prions are infectious proteins that, unlike viruses, contain no genetic
material (DNA or RNA).
True. Prions are misfolded proteins that cause diseases like mad cow disease and
Creutzfeldt-Jakob disease. They contain no nucleic acids.
4. Describe the primary mechanism by which the neurotoxin produced
by Clostridium botulinum causes flaccid paralysis.
The botulinum toxin prevents the release of the neurotransmitter acetylcholine at
neuromuscular junctions. This blocks nerve signals to muscles, leading to flaccid (limp)
paralysis.
5. Why is Gram-positive bacteria generally more susceptible to penicillin than
Gram-negative bacteria?
Penicillin inhibits peptidoglycan synthesis. Gram-positive bacteria have a thick,
exposed layer of peptidoglycan in their cell wall. Gram-negative bacteria have a thin
peptidoglycan layer that is covered by an outer membrane, which acts as a barrier and
prevents penicillin from easily reaching its target.
6. The ____________ is a gelatinous layer that surrounds the cell wall of some
bacteria and contributes to biofilm formation and evasion of the host immune
system.
Glycocalyx (or capsule/slime layer)
7. True or False. You would expect to find 80S ribosomes in the cytoplasm of a
bacterial cell.
False. Bacterial cells are prokaryotes and contain 70S ribosomes. Eukaryotic cells (e.g.,
human, fungal, plant) contain 80S ribosomes.
8. Rank the following microorganisms from largest to smallest typical size:
• Yeast cell
• Influenza virus
• Staphylococcus bacterium
/
