Question 1

Which of the following best describes the role of normal microbiota in human health?

Accepted Answer

They are microorganisms normally present and can prevent colonization by pathogens.

Question 2

A patient develops a gastrointestinal infection after ingesting contaminated food. Which term best describes the way the pathogen entered the body?

Accepted Answer

Portal of entry

Question 3

Which of the following is NOT a characteristic of the second line of defense in the immune system?

Accepted Answer

Antibody production by B-cells

Question 4

Which equation correctly represents the calculation of attack rate in epidemiology?

Accepted Answer

$$Attack\ Rate = \frac{Number\ of\ new\ cases}{Population\ at\ risk}$$

Question 5

Which of the following statements about Koch’s Postulates is correct?

Accepted Answer

They are used to determine if a specific disease is caused by a specific microorganism.

Question 6

A newborn receives IgG antibodies from the mother through the placenta. This is an example of:

Accepted Answer

Natural passive immunity

Question 7

Which of the following is a function of phagocytes in the immune response?

Accepted Answer

Engulfment and destruction of pathogens

Question 8

Which of the following best describes the difference between the primary and secondary immune response?

Accepted Answer

The secondary response is faster and stronger due to memory cells.

Question 9

Which type of vaccine contains killed or inactivated viruses?

Accepted Answer

Whole-cell vaccine

Question 10

A laboratory technician uses ELISA to detect the presence of a specific antigen in a patient’s serum. What is the principle behind this test?

Accepted Answer

It uses enzyme-linked antibodies to produce a color change when the antigen is present.

Question 11

Which of the following is a common misconception about herd immunity?

Accepted Answer

It means that every individual in the population is immune.

Question 12

Which antibody class is most abundant in serum and crosses the placenta to protect the fetus?

Accepted Answer

IgG

Question 13

A patient’s urine sample is tested for the presence of a specific bacterial antigen. Which laboratory test is most likely being performed?

Accepted Answer

UTI Panel

Question 14

Which of the following is a characteristic of inflammation?

Accepted Answer

Recruitment of immune cells and increased vascular permeability

Question 15

Which of the following is true regarding the transmission of infectious diseases?

Accepted Answer

Transmission can occur via biological or mechanical vectors.

Question 16

Which of the following is a function of T-helper cells (CD4+)?

Accepted Answer

Activation of B-cells and other immune cells

Question 17

Which of the following best describes the role of Florence Nightingale in microbiology?

Accepted Answer

She pioneered epidemiological methods in public health.

Question 18

Which of the following is a correct statement about the phases of disease progression?

Accepted Answer

The incubation phase is when the pathogen is multiplying but symptoms are not yet present.

Question 19

Which of the following is a common laboratory method for detecting viral infections such as hepatitis B?

Accepted Answer

ELISA

Question 20

Which of the following best describes the concept of latency in infectious diseases?

Accepted Answer

The period when the pathogen is present but not causing symptoms.

Microbiology and Host Defenses: Study Guide (Unit 3)

Study Guide - Practice Questions