Question 1

Which of the following best describes the difference between an endotoxin and an exotoxin?

Accepted Answer

Endotoxins are lipopolysaccharides found in the outer membrane of Gram-negative bacteria, while exotoxins are proteins secreted by both Gram-positive and Gram-negative bacteria.

Question 2

A patient develops a bacterial infection after a surgical procedure due to contamination from a non-sterile instrument. This type of infection is best described as:

Accepted Answer

Iatrogenic

Question 3

Which enzyme produced by certain bacteria allows them to break down the 'glue' that holds cells together, facilitating tissue invasion?

Accepted Answer

Hyaluronidase

Question 4

During which stage of infectious disease is a patient most likely to be contagious, even if they do not yet show symptoms?

Accepted Answer

Incubation

Question 5

Which of the following is an antiphagocytic virulence factor?

Accepted Answer

Capsule

Question 6

A disease that is constantly present at a low level in a specific geographic area is best described as:

Accepted Answer

Endemic

Question 7

Which of the following best differentiates incidence from prevalence in epidemiology?

Accepted Answer

Incidence measures new cases over a period of time, while prevalence measures all existing cases at a specific point in time.

Question 8

Which of the following is a granulocyte involved in allergic responses and the release of histamine?

Accepted Answer

Basophil

Question 9

Which type of lymphocyte matures in the thymus and is primarily responsible for cell-mediated immunity?

Accepted Answer

T lymphocyte

Question 10

Which of the following is NOT a physical barrier to infection?

Accepted Answer

Interferon

Question 11

Which of the following best describes the main function of eosinophils?

Accepted Answer

Combating parasitic infections and modulating allergic responses

Question 12

Which of the following is the correct sequence of the four cardinal signs of inflammation?

Accepted Answer

Redness, heat, swelling, pain

Question 13

Which of the following statements about the complement system is TRUE?

Accepted Answer

It leads to the formation of the membrane attack complex, opsonization, and inflammation.

Question 14

Which of the following best describes the main difference between B lymphocytes and T lymphocytes?

Accepted Answer

B lymphocytes produce antibodies (humoral immunity), while T lymphocytes are involved in cell-mediated immunity.

Question 15

Which of the following best defines an antigen?

Accepted Answer

A molecule that can be recognized by an antibody or T cell receptor and elicit an immune response

Question 16

Which of the following is a property of the adaptive immune response that allows it to respond to millions of different antigens using a limited number of genes?

Accepted Answer

Diversity achieved through gene recombination

Question 17

A plasma cell is best described as:

Accepted Answer

An effector cell derived from a B lymphocyte that secretes antibodies

Question 18

Which type of T lymphocyte expresses CD8, binds to MHC class I, and is responsible for killing virus-infected and tumor cells?

Accepted Answer

Cytotoxic T cell

Question 19

Which of the following best describes the function of perforins, and with which T cell type are they associated?

Accepted Answer

They are proteins that form pores in target cell membranes, associated with cytotoxic T cells.

Question 20

A patient is exposed to a novel virus and mounts an immune response. Upon a second exposure months later, the response is faster and stronger. This is best explained by which property of adaptive immunity?

Accepted Answer

Memory

Microbiology Study Guide: Infection, Immunity, and Epidemiology

Study Guide - Practice Questions

Study Guide - Flashcards