Question 1

Which of the following best describes the function of the complement system in nonspecific defense mechanisms?

Accepted Answer

It forms protein complexes that create holes in bacterial cell walls, leading to lysis.

Question 2

A patient is exposed to a pathogen for the first time. Which immune response is expected, and what is the typical lag time for antibody production?

Accepted Answer

Primary immune response; lag time of 3–6 days

Question 3

Which of the following is NOT a function of the lymphatic system?

Accepted Answer

Production of red blood cells

Question 4

Which antibody class is most prevalent in the blood and is responsible for long-term immunity?

Accepted Answer

IgG

Question 5

A virus is unable to reproduce outside of a host cell and lacks metabolic activity. Which structural feature distinguishes it from bacteria?

Accepted Answer

Protein coat surrounding either DNA or RNA

Question 6

Which of the following equations best represents the relationship between antibody concentration and time during a secondary immune response?

Accepted Answer

$$C_{antibody}(t) = C_{max} \cdot (1 - e$$^{-kt}$$)$$

Question 7

Which of the following is a characteristic of prions that makes them particularly difficult to eliminate from contaminated food?

Accepted Answer

They are resistant to freezing, drying, and cooking.

Question 8

A patient receives a kidney transplant. To minimize tissue rejection, which of the following must be matched between donor and recipient?

Accepted Answer

ABO blood group antigens and MHC antigens

Question 9

Which of the following best explains why antibiotics are ineffective against viral infections?

Accepted Answer

Viruses lack cell walls and metabolic pathways targeted by antibiotics.

Question 10

During an allergic reaction, which antibody class is primarily involved, and what is the role of histamine?

Accepted Answer

IgE; histamine causes inflammatory response

Question 11

Which of the following cells are responsible for antibody-mediated immunity and what is their site of maturation?

Accepted Answer

B cells; bone marrow

Question 12

A person is exposed to the influenza virus and develops immunity. Which mechanism is responsible for the rapid response upon re-exposure?

Accepted Answer

Activation of memory B and T cells

Question 13

Which of the following best describes the process of phagocytosis?

Accepted Answer

Phagocyte engulfs bacterium, forms vesicle, fuses with lysosome, digests bacterium, discards waste.

Question 14

Which of the following is a real-world example of a disease caused by prions?

Accepted Answer

Bovine spongiform encephalitis (mad cow disease)

Question 15

Which equation best represents the probability $$P of $$infection transmission given transmissibility $$T$$, mode of transmission efficiency $$E$$, and virulence $$V$$?

Accepted Answer

$$P = T \cdot E \cdot V$$

Question 16

Which of the following is a function of helper T cells in the immune response?

Accepted Answer

Secrete cytokines to stimulate other immune system cells

Question 17

A patient with lupus erythematosis is experiencing inflammation in multiple organs. Which immune system malfunction is responsible?

Accepted Answer

Autoimmune disorder: immune system attacks self tissues

Question 18

Which of the following best describes the role of MHC proteins in the immune system?

Accepted Answer

They are self-antigens that enable recognition of 'self' cells.

Question 19

Which of the following is a key difference between active and passive immunization?

Accepted Answer

Active immunization involves exposure to antigen; passive immunization involves administration of protective antibodies.

Question 20

Which of the following best explains why HIV infection leads to AIDS?

Accepted Answer

HIV targets helper T cells, reducing their numbers and impairing immune response.

Chapter 9: The Immune System and Mechanisms of Defense – Study Notes

Study Guide - Practice Questions

Study Guide - Flashcards