Question 1

Which of the following best describes the structure of a typical virus?

Accepted Answer

A protein capsid enclosing nucleic acid, sometimes surrounded by a lipid envelope derived from the host cell

Question 2

A patient is diagnosed with cervical cancer linked to a viral infection. Which virus is most likely responsible, and what is the mechanism by which it causes cancer?

Accepted Answer

Human papillomavirus (HPV); integrates its genome into host DNA, disrupting cell regulation

Question 3

During the multiplication cycle of animal viruses, which step immediately follows penetration?

Accepted Answer

Uncoating

Question 4

Which of the following is an example of a cytopathic effect (CPE) caused by viral infection?

Accepted Answer

Cell rounding and syncytia formation

Question 5

A virus is classified as a positive-sense, single-stranded RNA virus with a spherical envelope and spike glycoproteins. Which virus best fits this description?

Accepted Answer

Coronavirus

Question 6

Which of the following best explains why autoclaving is effective for sterilization?

Accepted Answer

It uses moist heat at $121^\circ\mathrm{C}$ and 15 psi to denature proteins and sterilize materials

Question 7

Which of the following statements about the therapeutic index (TI) of an antimicrobial drug is correct?

Accepted Answer

A higher TI indicates a safer drug because the toxic dose is much higher than the effective dose

Question 8

Which mechanism of action is shared by both beta-lactam antibiotics and cephalosporins?

Accepted Answer

Inhibition of cell wall synthesis

Question 9

A bacterial culture is in the exponential (log) phase of growth. Which of the following best describes what is occurring?

Accepted Answer

Cells are dividing at a constant and maximum rate

Question 10

Which of the following best describes a facultative anaerobe?

Accepted Answer

Can grow with or without oxygen

Question 11

A disinfectant is tested on a surface contaminated with bacterial spores. Which method is most likely to achieve sterilization?

Accepted Answer

Autoclaving at $121^\circ\mathrm{C}$ for 15 minutes

Question 12

Which of the following is a correct match between a viral family and a disease it causes?

Accepted Answer

Orthomyxoviridae: Influenza

Question 13

A microbiologist is culturing a thermophile. Which temperature range is most appropriate for optimal growth?

Accepted Answer

$50^\circ\mathrm{C}$ to $70^\circ\mathrm{C}$

Question 14

Which of the following best describes the action of surfactants as chemical control agents?

Accepted Answer

They disrupt cell membranes, aiding in the removal of microbes

Question 15

A patient is prescribed a combination of two antibiotics. The effect is greater than the sum of their individual effects. This is an example of:

Accepted Answer

Synergism

Question 16

Which of the following best explains why UV radiation is not always effective for sterilizing large volumes of liquid?

Accepted Answer

UV radiation has poor penetration and is only effective on surfaces

Question 17

Which of the following is the correct formula for calculating the therapeutic index (TI) of a drug?

Accepted Answer

$\mathrm{TI} = \frac{	ext{toxic dose}}{	ext{effective dose}}$

Question 18

Which of the following best describes the action of amphotericin B?

Accepted Answer

Targets fungal membranes by binding to ergosterol

Question 19

A researcher is studying a microbe that uses chemical compounds for energy. What is the correct term for this organism?

Accepted Answer

Chemotroph

Question 20

Which of the following is a correct match between a physical or chemical method and its main microbial target or effect?

Accepted Answer

Alcohol (chemical): Denatures proteins and disrupts membranes

Microbiology Study Guide: Viruses, Microbial Growth, and Control Methods

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