Question 1

Which of the following best describes the relationship in which one organism benefits while the other is neither helped nor harmed?

Accepted Answer

Commensalism

Question 2

A patient develops a urinary tract infection after being catheterized in a hospital. This infection is best classified as:

Accepted Answer

A healthcare-associated infection

Question 3

Which of the following is NOT a step in Koch’s postulates?

Accepted Answer

The microorganism must be found in all healthy individuals.

Question 4

A disease that is constantly present in a population, such as malaria in certain regions, is best described as:

Accepted Answer

Endemic

Question 5

Which of the following is a predisposing factor for disease?

Accepted Answer

All of the above

Question 6

A mosquito transmits malaria by injecting Plasmodium into a human host. This is an example of:

Accepted Answer

Biological transmission

Question 7

Which of the following best explains how bacterial capsules contribute to pathogenicity?

Accepted Answer

They help bacteria evade phagocytosis by host immune cells.

Question 8

A patient is exposed to a bacterial exotoxin. Which of the following is a likely effect?

Accepted Answer

Specific tissue damage due to protein toxins

Question 9

Which of the following is a correct statement about the innate immune system?

Accepted Answer

It includes physical barriers such as skin and mucous membranes.

Question 10

During inflammation, which process is responsible for the redness (erythema) observed at the site of injury?

Accepted Answer

Vasodilation

Question 11

Which of the following immune cells is primarily responsible for killing virus-infected cells in the innate immune response?

Accepted Answer

Natural killer (NK) cells

Question 12

Which complement pathway outcome is best described as the process by which pathogens are coated to enhance phagocytosis?

Accepted Answer

Opsonization

Question 13

Which type of T cell contains the CD8 receptor and is responsible for directly killing infected or abnormal cells?

Accepted Answer

Cytotoxic T cell

Question 14

Which class of immunoglobulin is the most abundant in serum and can cross the placenta to provide passive immunity to the fetus?

Accepted Answer

IgG

Question 15

A person receives a vaccine containing inactivated virus. This is an example of:

Accepted Answer

Artificial active immunity

Question 16

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

Accepted Answer

The secondary response involves memory cells and is more rapid and robust.

Question 17

Which of the following is a Type I hypersensitivity reaction?

Accepted Answer

Allergic reaction to pollen (hay fever)

Question 18

A laboratory technician mixes a patient’s serum with a known antigen and observes clumping. This test is based on which immunological principle?

Accepted Answer

Agglutination

Question 19

Which of the following best describes the role of Thelper2 (Th2) cells in the immune response?

Accepted Answer

They stimulate B cells to produce antibodies.

Question 20

A patient receives an injection of antivenom after a snake bite. This is an example of:

Accepted Answer

Artificial passive immunity

Epidemiology, Pathogenicity, Immunity, and Immune Disorders: Study Notes for Microbiology

Study Guide - Practice Questions