Question 1

Which of the following best describes the relationship between the human body and its normal microbiota?

Accepted Answer

The human body contains more bacterial cells than human cells, and many of these bacteria are beneficial.

Question 2

Which of the following is an example of mutualism in the human body?

Accepted Answer

Bacteria in the human colon producing vitamin K while receiving nutrients and shelter.

Question 3

Which site on the human body is most densely populated by anaerobic bacteria such as Bacteroides and Lactobacillus?

Accepted Answer

Intestines

Question 4

A fungus secretes an antibiotic that inhibits the growth of nearby bacteria, but the fungus is not affected. What type of symbiotic relationship is this?

Accepted Answer

Amensalism

Question 5

Which of the following conditions can turn normal microbiota into opportunistic pathogens?

Accepted Answer

All of the above

Question 6

Which of the following is a nonliving reservoir of infection?

Accepted Answer

Soil contaminated with feces

Question 7

Which of the following best describes the difference between incidence and prevalence?

Accepted Answer

Incidence is the number of new cases during a specific time; prevalence is the total number of cases at a given time.

Question 8

Which of the following is a correct example of zoonosis?

Accepted Answer

Rabies virus transmitted from a bat to a human via a bite

Question 9

Which of the following is a sign, not a symptom, of disease?

Accepted Answer

Fever

Question 10

Which of the following best describes the role of Rhizobium bacteria in the rhizosphere?

Accepted Answer

They fix atmospheric nitrogen into a form usable by plants, benefiting both the bacteria and the plant.

Question 11

A patient is infected with a pathogen but does not show any symptoms. However, laboratory tests reveal the presence of the pathogen. What is this type of infection called?

Accepted Answer

Asymptomatic (subclinical) infection

Question 12

Which of the following is a vehicle mode of disease transmission?

Accepted Answer

Inhaling aerosolized droplets from a sneeze

Question 13

Which of the following best explains why breastfed infants have a different gut microbiota compared to formula-fed infants?

Accepted Answer

Breast milk contains unique carbohydrates that feed specific beneficial bacteria.

Question 14

Which of the following is a correct statement about exotoxins?

Accepted Answer

They are proteins secreted by bacteria and can cause damage to host tissues.

Question 15

A disease that is constantly present in a population, often at a low level, is best described as:

Accepted Answer

Endemic

Question 16

Which of the following best describes the prodromal period of an infectious disease?

Accepted Answer

The period with vague, general symptoms before the illness phase.

Question 17

Which of the following is a plausible outcome if a person is exposed to a dose of Mycobacterium tuberculosis lower than the infectious dose (ID)?

Accepted Answer

The person is unlikely to develop an infection.

Question 18

Which of the following is a correct example of a biological vector in disease transmission?

Accepted Answer

A mosquito transmitting malaria by serving as an intermediate host.

Question 19

Which of the following best describes the term 'herd immunity'?

Accepted Answer

Immunity in most of a population, reducing the spread of disease.

Question 20

Which of the following is a plausible reason why an acute disease with a high mortality rate is unlikely to cause a pandemic?

Accepted Answer

High mortality limits the time for transmission to new hosts.

Chapter 14

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Study Guide - Flashcards