Question 1

Which of the following best explains why viruses are considered acellular?

Accepted Answer

They lack cellular structures such as ribosomes and a plasma membrane.

Question 2

Which structure is present in bacteria but absent in viruses?

Accepted Answer

Ribosome

Question 3

Reverse transcriptase is an enzyme found in which group of viruses, and what is its primary function?

Accepted Answer

Retroviruses; it synthesizes DNA from RNA templates.

Question 4

A patient presents with intense itching in the anus and is diagnosed with enterobiasis. Which organism is responsible, and what is the most effective diagnostic method?

Accepted Answer

Enterobius vermicularis; Scotch tape method for microscopic ova

Question 5

Which of the following is a defining feature of prions?

Accepted Answer

They are infectious proteins lacking nucleic acids.

Question 6

Which of the following best describes the lytic cycle of a bacteriophage?

Accepted Answer

The virus immediately replicates and lyses the host cell, releasing new virions.

Question 7

Which of the following is NOT a function of the H and N spikes found on influenza viruses?

Accepted Answer

N spike is responsible for viral genome replication.

Question 8

Which of the following statements about fungal reproduction is correct?

Accepted Answer

Fungi can reproduce both sexually and asexually, often forming spores.

Question 9

A patient with AIDS presents with cysts that resemble crushed ping pong balls. Which organism is most likely responsible?

Accepted Answer

Pneumocystis carinii (P. jiroveci)

Question 10

Which of the following is the definitive host for Plasmodium falciparum?

Accepted Answer

Anopheles mosquito

Question 11

Which equation correctly represents the calculation of viral titer using the plaque assay method?

Accepted Answer

$\mathrm{Viral\ titer} = \frac{\mathrm{Number\ of\ plaques}}{\mathrm{Volume\ plated} 	imes \mathrm{Dilution\ factor}}$

Question 12

Which of the following is a distinguishing feature of dimorphic fungi?

Accepted Answer

They can exist as both yeast and mold forms depending on environmental conditions.

Question 13

Which protozoan is transmitted by the Anopheles mosquito and what disease does it cause?

Accepted Answer

Plasmodium falciparum; malaria

Question 14

Which of the following is the most accurate method for diagnosing Giardia duodenalis infection?

Accepted Answer

Observing for trophozoite or cyst from stool under microscopy

Question 15

Which of the following statements about the eclipse period in bacteriophage culture is correct?

Accepted Answer

It is the period when no infectious phage particles are detected inside the host cell.

Question 16

Which of the following is NOT a mode of transmission for Toxoplasma gondii?

Accepted Answer

Inhalation of fungal spores

Question 17

Which of the following best describes the function of vegetative hyphae in fungi?

Accepted Answer

They absorb nutrients and anchor the fungus to the substrate.

Question 18

Which organism is carried by the Xenopsylla rat flea and what disease does it cause?

Accepted Answer

Yersinia pestis; plague

Question 19

Which of the following is a common issue in the development of antiviral agents?

Accepted Answer

Viruses use host cell machinery, making selective targeting difficult.

Comprehensive Study Guide: Microbiology of Bacteria, Viruses, Fungi, Protozoa, and Helminths

Study Guide - Practice Questions

Study Guide - Flashcards