Question 1

Which of the following best explains why viruses are classified as nonliving microbes?

Accepted Answer

Viruses do not exhibit metabolism, have no cells, and require a host to replicate.

Question 2

Which of the following is a major difference between prokaryotic cells and viruses, according to Table 6.1?

Accepted Answer

Viruses lack cellular structure and do not have ribosomes, while prokaryotes have both.

Question 3

A pathogen must complete several general tasks to cause disease. Which of the following is the correct sequence?

Accepted Answer

Find a host, adhere to host tissues, invade tissues, evade immune defenses, transmit to new host.

Question 4

Which statement best describes the role of bacteriophages in bacterial populations?

Accepted Answer

Bacteriophages kill bacteria, shaping microbial communities and can be used to control pathogenic bacteria.

Question 5

Which of the following best describes antigenic shift in influenza viruses?

Accepted Answer

Major genetic reassortment resulting in new highly virulent strains.

Question 6

Antigenic drift in influenza viruses is characterized by:

Accepted Answer

Frequent minor mutations in the RNA genome causing gradual changes in HA and NA spikes.

Question 7

Which of the following viruses is NOT associated with persistent infections that can lead to cancer?

Accepted Answer

Influenza virus

Question 8

Oncogenic viruses can cause cancer by which of the following mechanisms?

Accepted Answer

Stimulating uncontrolled host cell division and decreasing cell responsiveness to death signals.

Question 9

Which of the following is an example of direct contact transmission of a pathogen?

Accepted Answer

Shaking hands with an infected person.

Question 10

Which anatomical feature of the skin provides a physical barrier to microbial invasion?

Accepted Answer

Outer layer of tightly packed dead cells containing keratin.

Question 11

Which factor does NOT impact the composition of the skin microbiome?

Accepted Answer

Blood type

Question 12

Which defense mechanism of the skin is responsible for washing away some microbes?

Accepted Answer

Hand washing and bathing

Question 13

Which portal of entry is most commonly associated with respiratory pathogens?

Accepted Answer

Mucous membranes of the respiratory tract

Question 14

A maculopapular rash is best described as:

Accepted Answer

Raised solid lesion (not fluid-filled) with discoloration and distinct borders.

Question 15

Which of the following is a distinguishing feature of shingles compared to chickenpox?

Accepted Answer

Shingles presents as a band of blisters on one side of the body, often with burning pain.

Question 16

Which of the following best describes a persistent viral infection?

Accepted Answer

Virus replicates continuously, releasing virions over time and causing slow progression of disease.

Question 17

Which virus is known for causing latent infections that can reactivate later in life?

Accepted Answer

Varicella-zoster virus (VZV)

Question 18

A vesicle is defined as:

Accepted Answer

A small, elevated lesion filled with clear fluid.

Question 19

Which of the following is a real-world example of indirect contact transmission?

Accepted Answer

Touching a doorknob contaminated with pathogens and then touching your mouth.

Question 20

Which equation best represents the process of antigenic drift in influenza viruses?

Accepted Answer

$$ 	ext{Antigenic Drift:} \quad 	ext{HA}_{	ext{old}} + 	ext{mutation} ightarrow 	ext{HA}_{	ext{new}} $$

Microbiology Study Notes: Viruses, Pathogenicity, Skin Defenses, and Disease Transmission

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