Q: Which of the following equations correctly represents the calculation of burst size in a lytic viral infection?

$$\text{Burst Size} = \frac{\text{Number of newly assembled viruses released}}{\text{Number of infected host cells}}$$

Question 1

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

Accepted Answer

They lack cytoplasm, organelles, and an active membrane, and cannot metabolize or reproduce independently.

Question 2

A scientist is studying a virus that infects only bacteria and causes clear circular areas on a lawn of bacteria after infection. What is the most likely term for this virus and the clear areas observed?

Accepted Answer

Bacteriophage and plaques

Question 3

Which of the following best describes the function of glycoproteins on the surface of a viral envelope?

Accepted Answer

They serve as recognition sites that bind to complementary receptors on the host cell.

Question 4

A virus with an icosahedral capsid and a phospholipid envelope is released from the host cell by budding. Which of the following is TRUE about this process?

Accepted Answer

The virus acquires its envelope from the host cell membrane during release.

Question 5

Which of the following equations correctly represents the calculation of burst size in a lytic viral infection?

Accepted Answer

$$	ext{Burst Size} = \frac{	ext{Number of newly assembled viruses released}}{	ext{Number of infected host cells}}$$

Question 6

Which of the following is a key difference between the lytic and lysogenic cycles of bacteriophage replication?

Accepted Answer

The lysogenic cycle allows the viral genome to be replicated along with the host genome without immediate destruction of the host cell.

Question 7

A patient is diagnosed with a disease caused by a prion. Which of the following statements about prions is CORRECT?

Accepted Answer

Prions are infectious proteins that induce abnormal folding of normal cellular proteins.

Question 8

Which of the following best describes the process of viral entry into an animal cell by membrane fusion?

Accepted Answer

The viral envelope fuses with the host cell membrane, allowing the capsid to enter the host cell where it is then uncoated.

Question 9

Which of the following is a characteristic of viroids that distinguishes them from viruses?

Accepted Answer

Viroids are small, circular RNA molecules that lack a protein capsid and infect plants.

Question 10

A researcher is working with a continuous cell culture derived from cancer cells. Which of the following is TRUE about this type of culture?

Accepted Answer

It can be maintained for many generations and is often used for viral cultivation.

Question 11

Which of the following best explains how viruses can contribute to the development of cancer in host cells?

Accepted Answer

Viruses can carry oncogenes or activate host proto-oncogenes, leading to uncontrolled cell division.

Question 12

Which of the following is NOT a function of the viral capsid?

Accepted Answer

Synthesizing viral nucleic acids

Question 13

A virus is classified as a 'naked virus.' Which of the following statements is TRUE regarding its structure and release?

Accepted Answer

It lacks an envelope and is typically released from the host cell by lysis or exocytosis.

Question 14

Which of the following best describes the role of lysozyme in bacteriophage infection?

Accepted Answer

It weakens the bacterial cell wall to allow entry of the viral genome.

Question 15

Which of the following is a correct statement about the genetic material of viruses?

Accepted Answer

A virus can have either DNA or RNA, which may be single-stranded or double-stranded.

Question 16

A patient develops a fatal neurodegenerative disease after consuming contaminated beef. Which of the following is the most likely cause?

Accepted Answer

A prion disease such as variant Creutzfeldt-Jakob disease (vCJD)

Question 17

Which of the following best describes the process of induction in lysogenic bacteriophage replication?

Accepted Answer

The prophage is excised from the host chromosome and the virus enters the lytic cycle.

Question 18

Which of the following is a unique feature of prions compared to all other infectious agents?

Accepted Answer

They lack nucleic acids and are composed solely of misfolded proteins.

Question 19

Which of the following is the correct sequence of steps in the basic viral replication cycle?

Accepted Answer

Attachment, entry, synthesis, assembly, release

Question 20

A virus is found to have a helical capsid structure. Which of the following best describes this structure?

Accepted Answer

Capsomers are bonded together in a spiral formation around the nucleic acid.

Acellular Infectious Agents: Viruses, Viroids, and Prions

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