Question 1

Which of the following best describes the structure and function of a viral capsid?

Accepted Answer

A protein coat built from capsomeres that encloses the viral genome.

Question 2

Which type of virus is most likely to infect bacteria and is characterized by a complex structure with a polyhedral head and tail fibers?

Accepted Answer

Complex virus (bacteriophage)

Question 3

A virus with a helical capsid and RNA genome infects a plant. Which virus is this most similar to?

Accepted Answer

Tobacco Mosaic Virus

Question 4

Which of the following is TRUE about viral envelopes?

Accepted Answer

They contain glycoproteins that bind to specific receptors on host cells.

Question 5

What is the main difference between the lytic and lysogenic cycles of bacteriophages?

Accepted Answer

The lytic cycle results in the destruction of the host cell, while the lysogenic cycle allows the viral genome to persist in the host without killing it.

Question 6

Which equation best represents the exponential growth of viral particles during the lytic cycle, assuming each infected cell releases $$N$$ new viruses and $$t is $$the number of cycles?

Accepted Answer

$$V = N^t$$

Question 7

A patient is resistant to HIV infection due to a mutation in a cell-surface protein. Which protein is most likely mutated?

Accepted Answer

CCR5 co-receptor

Question 8

Which of the following statements about retroviruses is correct?

Accepted Answer

Retroviruses use reverse transcriptase to convert their RNA genome into DNA.

Question 9

If a new virus emerges and causes an epidemic in mammals, which property would most likely contribute to its rapid spread?

Accepted Answer

It is capable of aerosol transmission and survives in droplets.

Question 10

Which of the following best explains why viruses are considered to exist in a 'shady area' between life-forms and chemicals?

Accepted Answer

Viruses are composed of genes packaged in protein coats but require host cells to reproduce.

Question 11

Which of the following is a plausible reason why influenza viruses can cause epidemics in mammals?

Accepted Answer

They can cross species barriers and undergo genetic reassortment.

Question 12

A scientist discovers a virus with a polyhedral capsid and glycoproteins on its surface. Which type of virus is this most likely to be?

Accepted Answer

Polyhedral virus

Question 13

Which of the following is NOT a method by which viruses can be transmitted between hosts?

Accepted Answer

Photosynthesis

Question 14

Which of the following best describes the role of viral glycoproteins in infection?

Accepted Answer

They bind to specific receptors on host cell surfaces to facilitate entry.

Question 15

If the total number of viruses on Earth could stretch to our nearest galactic neighbor and back forty times, and the distance to Andromeda is $$2.5$$ million light-years one way, what is the total distance covered by the viruses?

Accepted Answer

$$100$$ million light-years

Question 16

Which of the following is a key feature that distinguishes animal viruses with envelopes from those without?

Accepted Answer

Enveloped viruses use glycoproteins to bind to host cell receptors.

Question 17

During the HIV replicative cycle, which enzyme is responsible for synthesizing DNA from the viral RNA genome?

Accepted Answer

Reverse transcriptase

Question 18

Which of the following scenarios best illustrates the concept of an emerging virus?

Accepted Answer

A virus that jumps from animals to humans and causes a new outbreak.

Question 19

Which of the following is a plausible consequence of genetic reassortment in influenza viruses?

Accepted Answer

Creation of new viral strains capable of infecting different species

Question 20

A virus infects a host cell and integrates its genome into the host's DNA, remaining dormant for several generations. Which viral cycle is this describing?

Accepted Answer

Lysogenic cycle

Viruses: Structure, Diversity, and Replication (Campbell Biology in Focus, Chapter 17)

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