Question 1

Which of the following statements best explains why viruses are considered obligate intracellular parasites?

Accepted Answer

They can only replicate and carry out metabolic activities inside a host cell.

Question 2

A scientist discovers a new infectious agent that contains only misfolded proteins, no nucleic acids, and is highly resistant to heat. Which disease is most likely associated with this agent?

Accepted Answer

Creutzfeldt-Jakob Disease

Question 3

Which of the following correctly describes the genetic material found in a single virus particle?

Accepted Answer

It contains either DNA or RNA, but never both.

Question 4

A patient is diagnosed with a respiratory infection caused by a virus with a lipid envelope and glycoprotein spikes, and the virus has a high rate of recombination. Which virus is most likely responsible?

Accepted Answer

SARS-CoV-2

Question 5

Which of the following best explains why prions are not classified as viruses?

Accepted Answer

Prions lack nucleic acids, while viruses contain either DNA or RNA.

Question 6

Which of the following is a key structural difference between a naked virus and an enveloped virus?

Accepted Answer

An enveloped virus has an external lipid bilayer with glycoprotein spikes, while a naked virus does not.

Question 7

Which process allows retroviruses such as HIV to integrate their genetic material into the host genome?

Accepted Answer

Reverse transcription of viral RNA into DNA by reverse transcriptase

Question 8

A virus is found to have a segmented, double-stranded RNA genome and a protein coat made of capsomeres. Which of the following structures is NOT present in this virus?

Accepted Answer

Ribosomes

Question 9

Which of the following best describes antigenic drift and its impact on influenza immunity?

Accepted Answer

Gradual changes in viral surface antigens reduce the effectiveness of existing antibodies.

Question 10

A patient is exposed to a zoonotic virus that causes about 15% of common colds and is characterized by a 'crown' appearance under the microscope. Which of the following statements is TRUE regarding this virus?

Accepted Answer

It is an RNA virus with a lipid envelope and glycoprotein spikes.

Question 11

Which of the following equations best represents the process by which retroviruses synthesize DNA from their RNA genome?

Accepted Answer

$ RNA \rightarrow DNA $

Question 12

A researcher is studying a virus that can exist in multiple segments and is covered by a protein coat. What is the name of the protein subunits that make up this coat?

Accepted Answer

Capsomeres

Question 13

Which of the following is TRUE regarding the difference between SARS-CoV-2 and Covid-19?

Accepted Answer

SARS-CoV-2 is the virus, while Covid-19 is the disease caused by the virus.

Question 14

Which of the following best explains why prion diseases are difficult to eliminate from contaminated environments?

Accepted Answer

Prions are highly resistant to heat and common disinfectants.

Question 15

A virus infects a host cell and integrates its DNA into the host genome, remaining dormant for years before producing new viruses. What is this integrated viral DNA called?

Accepted Answer

Provirus

Question 16

Which of the following is a real-world example of a disease caused by prions?

Accepted Answer

Mad Cow Disease (Bovine Spongiform Encephalopathy)

Question 17

A virus is measured to be 100 nanometers in diameter. What is this size in meters?

Accepted Answer

$ 1 	imes 10^{-7} $ meters

Question 18

Which of the following best describes the function of hemagglutinin and neuraminidase in influenza viruses?

Accepted Answer

They are surface antigens that play a role in viral entry and release from host cells.

Question 19

A patient is infected with a virus that lacks a plasma membrane, ribosomes, and organelles, but has a protein coat and a single-stranded RNA genome. Which of the following statements is TRUE about this virus?

Accepted Answer

It cannot carry out metabolic activities on its own.

Question 20

Which of the following scenarios best illustrates antigenic shift in influenza viruses?

Accepted Answer

A human influenza virus and an avian influenza virus exchange genetic material, creating a new viral strain.

Viruses: Structure, Replication, and Disease

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