Practice 47 MCQs on MICROBIOLOGY AND PARASITOLOGY MCQs with OmpathStudy. Built for Kenyan medical and health students to revise key concepts and prepare for...
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Q1. Which one of the following is an intracellular parasite?
- *Trypanosoma brucei rhodesiense*
- *Trichomonas vaginalis*
- *Entamoeba histolytica*
- *Leishmania donovani*
- All of the above
- *Leishmania donovani *
Answer: *Leishmania donovani*
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Q2. Parasites can be classified based on their hosts. Which one of the following statements classifies a Mesoparasite ?
- A parasite which is occasionally found in both intermediate and definitive host
- A parasite which entirely lives in an intermediate host
- A parasite which entirely lives in a definitive host
- A parasite which partly lives in and on a host
- None of the above
- A parasite which partly lives in and on a host
Answer: A parasite which partly lives in and on a host
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Q3. Single-celled parasites utilize various physiological modes to take in molecules. Which one of the following is adopted for intake of a molecule for mutualism existence within the parasite?
- Endocytosis
- Active transport
- Pinocytosis
- Exocytosis
- None of the above
- Endocytosis
Answer: Endocytosis
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Q4. The following are genetic-based conditions which can lead to resistance against malaria infection EXCEPT ?
- Sickle cell trait
- Thalassemia
- Presence of Glucose-6-phosphate dehydrogenase
- Absence of Duffy antigens
- None of the above
- Presence of Glucose-6-phosphate dehydrogenase
Answer: Presence of Glucose-6-phosphate dehydrogenase
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Q5. In which form does Fasciola hepatica get into the human host?
- Eggs
- Cercariae
- Trophozoites
- Metacercariae
- Larvae
- Metacercariae
Answer: Metacercariae
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Q6. Malaria infection is characterized by paroxysms. What is the interval of these paroxysms in a Plasmodium vivax infection?
- 24 hours
- 96 hours
- 48 hours
- 72 hours
- 12 hours
- 48 hours
Answer: 48 hours
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Q7. Which of the following parasites can be diagnosed by cerebrospinal fluid biopsy?
- *Giardia lamblia*
- *Ascaris lumbricoides*
- *Trichinella spiralis*
- *Taenia solium*
- All of the above
- *Taenia solium *
Answer: *Taenia solium*
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Q8. Trichomonas vaginalis is characterized by how many flagella?
Answer: Five
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Q9. Which of the following is NOT true about bacterial flagella?
- Most of their length consists of a hollow, rigid protein tube.
- They are constructed largely of a single protein called flagellin.
- They spin like wheels, either clockwise or counterclockwise.
- They use cytoplasmic ATP as their primary energy source.
- None of the above
- They use cytoplasmic ATP as their primary energy source.
Answer: They use cytoplasmic ATP as their primary energy source.
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Q10. What is the purpose of bacterial endospores?
- Allow the bacterium to make hundreds of "seeds" to spread on the wind.
- Help the bacterium differentiate into faster-growing stages.
- Allow the bacterium to survive the absence of oxygen.
- Allow the bacterium to survive extended periods of heat or dryness.
- All of the above
- Allow the bacterium to survive extended periods of heat or dryness.
Answer: Allow the bacterium to survive extended periods of heat or dryness.
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Q11. Cells containing many nuclei are called
- Coenocyte
- Hyphae
- Mycelium
- Sporophore
- None of the above
- Coenocyte
Answer: Coenocyte
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Q12. The group or mass of hyphae is
- Coenocyte
- Hyphae
- Mycelium
- Sporophore
- B and C
- B and C
Answer: B and C
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Q13. The spores produced inside the sporangia are
- Conidia
- Endospore
- Zoospore
- Sporangiospores
- Microspores
- Sporangiospores
Answer: Sporangiospores
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Q14. The spores produced at the tip of hyphae outside the sporangia are
- Conidia
- Endospore
- Zoospore
- Oidia
- Sporangiospores
- Conidia
Answer: Conidia
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Q15. In some fungi, the hyphae break up into individual cells. These cells behave as spores and are called
- Blastospores
- Endospore
- Zoospore
- Arthrospores
- Conidiaspores
- Arthrospores
Answer: Arthrospores
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Q16. The most crucial step in infection of a host cell by a virus is
- Adsorption
- Attachment
- Penetration
- Replication
- Release
- Penetration
Answer: Penetration
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Q17. The viral nucleocapsid is the combination of
- Genome and capsid
- Capsid and spikes
- Envelope and capsid
- Capsomere and genome
- Genome and spikes
- Genome and capsid
Answer: Genome and capsid
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Q18. In the absence of cytopathic effects (CPE), how would one demonstrate that a permissive cell is infected by a virus?
- By Immunofluorescence Test (IFT)
- By plaque test
- By cell counting
- By hemagglutination assay
- None of the above
- By Immunofluorescence Test (IFT)
Answer: By Immunofluorescence Test (IFT)
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Q19. What is a phage?
- Bacterium that infects viruses
- A virus that infects bacteria
- A bacterium that infects animal cells
- An arbovirus
- Virus-transformed cell
- A virus that infects bacteria
Answer: A virus that infects bacteria
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Q20. Prevention of viral diseases is best achieved by
- Antibiotics
- Use of condoms
- Vaccination
- Antiviral drugs
- All of the above
- Vaccination
Answer: Vaccination
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Q21. A chemical component that is found in all viruses is
- Protein-coated nucleic acid
- Lipid
- DNA
- RNA
- All of the above
- Protein-coated nucleic acid
Answer: Protein-coated nucleic acid
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Q22. Interferons are
- Synthesized by the virus when infecting a cell
- Synthesized by the host cell when infected by a virus
- Synthesized by defective particles during infection
- Synthesized by subviral agents in the cell during infection
- A and B
- Synthesized by the host cell when infected by a virus
Answer: Synthesized by the host cell when infected by a virus
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Q23. During what stage of the viral life cycle is the nucleic acid packed inside the capsid?
- Penetration
- Late protein synthesis (capsid)
- Early protein synthesis
- Assembly
- At the time of uncoating
- Assembly
Answer: Assembly
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Q24. Which types of viruses contain reverse transcriptase?
- Herpes viruses
- Adenoviruses
- Influenza viruses
- Retroviruses
- All single-stranded RNA viruses
- Retroviruses
Answer: Retroviruses
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Q25. A phage that exhibits both lytic and lysogenic life cycles is called
- Prophage
- Provirus
- Virulent
- Temperate
- Plaque
- Temperate
Answer: Temperate
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Q26. In which type of virus is the production of double-stranded DNA from RNA a necessary intermediate in the life cycle?
- Influenza virus
- Polio virus
- Herpes virus
- Retrovirus
- T-even phage
- Retrovirus
Answer: Retrovirus
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Q27. The significance of the plasma membrane is that
- It selectively allows some molecules to pass into the organism.
- It prevents movement of molecules out of the organism.
- It is the site of protein synthesis.
- B and C
- All of the above
- It selectively allows some molecules to pass into the organism.
Answer: It selectively allows some molecules to pass into the organism.
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Q28. Commonly encountered bacteria are roughly spherical. The microbiological term describing this shape is
- Coccus
- Coccobacillus
- Pleomorphic
- None of the above
- Coccus and sometimes coccobacillus
- Coccus
Answer: Coccus
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Q29. Another common bacterial shape is that of a rod, often called
- Coccus
- Bacillus
- Pleomorphic
- Vibrio
- None of the above
- Bacillus
Answer: Bacillus
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Q30. In bacterial cells, ribosomes are packed into the cytoplasmic matrix and also loosely attached to the plasma membrane. What is the function of ribosomes?
- Site of energy production
- Site of protein synthesis
- Site of genetic reproduction
- Both A and B
- None of the above
- Site of protein synthesis
Answer: Site of protein synthesis
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Q31. What is a plasmid?
- Self-replicating segment of double-stranded DNA
- Self-replicating segment of single-stranded RNA
- A bacterial chromosome
- All of the above
- None of the above
- Self-replicating segment of double-stranded DNA
Answer: Self-replicating segment of double-stranded DNA
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Q32. Plasmids are important to the genetics of many bacteria because
- They are inherited from one generation to the next.
- They may carry genes that give their host a selective advantage.
- They can render bacteria drug-resistant.
- All of the above.
- They facilitate lysogeny.
- All of the above.
Answer: All of the above.
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Q33. Some bacteria are considered pleomorphic. This means
- They are shaped like bent rods.
- They have a corkscrew shape.
- They do not have just one shape.
- They are restricted to one biotope.
- They are not either bacilli or cocci.
- They do not have just one shape.
Answer: They do not have just one shape.
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Q34. The 70S prokaryotic ribosomes consist of
- Two 40S subunits.
- A 50S and a 30S subunit.
- A 40S and a 30S subunit.
- A 50S and a 20S subunit.
- A 20S and a 60S subunit.
- A 50S and a 30S subunit. --
Answer: A 50S and a 30S subunit.
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Q35. Gram-positive cells:A) Have thick, homogeneous cell walls.
- Have large amounts of teichoic acids.
- Have large molecular chitins.
- Do not have an outer membrane.
- All of the above are true.**
Answer: Have large amounts of teichoic acids.
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Q36. The outer membrane of Gram-negative cells is more permeable than the plasma membrane because:A) LPS is larger than most membrane phospholipids.
- Lipoproteins stretch the outer membrane.
- Porin proteins establish holes in the outer membrane.**
- The core polysaccharide spans the lipid bilayer.
- None of the above.**Answer:
Answer: Lipoproteins stretch the outer membrane.
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Q37. The most important role of the prokaryotic cell wall is to:A) Maintain the shape of the cell.
- Protect the cell from osmotic pressures.**
- Prevent ions from diffusing away from the cell.
- Block the effects of antibiotics like penicillin.
- All of the above.**Answer:
Answer: Protect the cell from osmotic pressures.**
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Q38. Which of the following is NOT true about capsules and slime layers?A) They consist of secreted material lying outside of the bacterial cell wall.
- They can prevent desiccation of bacterial cells.
- They are required for bacteria to grow normally in culture.**
- They help bacteria resist phagocytosis by macrophages.
- None of the above.**Answer:
Answer: They can prevent desiccation of bacterial cells.
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Q39. Fimbriae:A) Attach bacteria to various surfaces.
- Cause bacteria to move through fluids.
- Sense changes in nutrient concentration.
- Are pathways for the secretion of exoenzymes.
- C and D.**Answer: A) Attach bacteria to various surfaces.**
Answer: Cause bacteria to move through fluids.
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Q40. A bacillus bacterium with a single flagellum at each end is described as:A) Monotrichous
- Amphitrichous**
- Lophotrichous
- Peritrichous
- All of the above**Answer:
Answer: Amphitrichous**
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Q41. Bacterial capsules are useful for:A) Attachment to surfaces.
- Protection against macrophages.**
- Production of toxins.
- Motility.
- Reproduction.**Answer:
Answer: Protection against macrophages.**
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Q42. Which of the following is a true pathogen ?A) Candida
- *Sporothrix***
- *Mucor*
- *Aspergillus*
- None**Answer:
Answer: *Sporothrix***
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Q43. Bacterial capsules are best demonstrated by:A) Methylene blue stain.
- Gram stain.
- Negative staining.**
- Impregnation technique.
- None of the above.**Answer:
Answer: Gram stain.
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Q44. In a light microscope, what function does the condenser serve?A) Focuses the light rays on the sample.
- Magnifies the light rays after their passage through the sample.
- Focuses the light rays into the observer’s eyes.
- Increases the light intensity.
- Reduces glare.**Answer: A) Focuses the light rays on the sample.**
Answer: Magnifies the light rays after their passage through the sample.
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Q45. One of the diseases below is not caused by bacteria:A) Leprosy
- Plague
- Rabies**
- Tetanus
- Meningitis**Answer:
Answer: Plague
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Q46. The presence of D-amino acids in the crosslinks of the peptidoglycan layer is most likely because:A) Most peptidases can only cleave L-amino acids.
- D-amino acids fit the structural constraints of the cell wall better than L-amino acids.
- Most L-amino acids have already been used for protein synthesis.
- D-amino acids are easier to crosslink in the absence of ribosomes.
- They promote synthesis of much-needed essential amino acids.**Answer: A) Most peptidases can only cleave L-amino acids.**
Answer: D-amino acids fit the structural constraints of the cell wall better than L-amino acids.
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Q47. Which of the following is not a characteristic of fungi?A) Can be unicellular or multicellular.
- Have cell walls made of chitin.
- Are photosynthetic.**
- Can produce antibiotics.
- Can be infected by viruses.**Answer:
Answer: Have cell walls made of chitin.