Question 1

Which of the following is a key reason why viruses cannot be cultured in standard microbiological media?

Accepted Answer

Viruses require host cells for replication.

Question 2

A researcher wants to estimate the number of bacteriophages in a sample. Which laboratory technique should they use?

Accepted Answer

Plaque assay

Question 3

Why are embryonated chicken eggs commonly used for culturing certain viruses?

Accepted Answer

They provide a large, contaminant-free environment with nourishing yolk.

Question 4

Which of the following statements about prions is correct?

Accepted Answer

Prions are infectious proteins that cause normal proteins to misfold.

Question 5

A patient develops spongiform encephalopathy after receiving a corneal transplant. What is the most likely infectious agent?

Accepted Answer

Prion

Question 6

Which of the following best describes a viroid?

Accepted Answer

An infectious, circular piece of ssRNA lacking a capsid

Question 7

Which method is approved by the European Union for removing prions from medical equipment?

Accepted Answer

Enzymatic treatment

Question 8

Which of the following is NOT a type of symbiotic relationship between microbes and hosts?

Accepted Answer

Antagonism

Question 9

Resident microbiota are best described as:

Accepted Answer

Microorganisms that are part of the normal flora throughout life

Question 10

Which condition can turn normal microbiota into opportunistic pathogens?

Accepted Answer

Immune suppression

Question 11

A zoonosis is best defined as:

Accepted Answer

A disease that naturally spreads from animal hosts to humans

Question 12

Which of the following is a nonliving reservoir of infectious disease?

Accepted Answer

Soil

Question 13

Which of the following equations would you use to estimate the concentration of phages in a sample using a plaque assay?

Accepted Answer

$$C = \frac{P}{V}$$

Question 14

Which of the following is a plausible reason why laboratory animals are not always used for culturing viruses?

Accepted Answer

They are expensive and raise ethical concerns.

Question 15

Which of the following is true about transient microbiota?

Accepted Answer

They remain in the body for a short period and cannot persist due to competition and elimination.

Question 16

Which of the following is a correct statement about the transmission of prion diseases?

Accepted Answer

They can be transmitted by ingestion, transplantation, or contact with infected tissues.

Question 17

Which of the following is a characteristic feature of spongiform encephalopathies caused by prions?

Accepted Answer

Large vacuoles form in brain tissue, giving it a spongy appearance.

Question 18

Which of the following best explains why prions are resistant to standard sterilization procedures?

Accepted Answer

Their protein structure is highly stable and not denatured by conventional methods.

Question 19

Which of the following is a plausible consequence of introducing normal microbiota into an unusual site in the body?

Accepted Answer

Development of an opportunistic infection

Question 20

Which of the following is the correct sequence for the development of the human microbiome?

Accepted Answer

Womb is sterile, microbiome develops during birth and first months of life.

Culturing Viruses in the Laboratory: Methods and Applications

Study Guide - Practice Questions