$$\text{Antigen} + \text{Antibody} \rightarrow \text{Antigen-Antibody Complex}$$

Question 1

Which of the following best describes the function of keratin in the skin's surface barrier?

Accepted Answer

Keratin forms a waterproof, physical barrier resistant to acids, bases, toxins, and some enzymes.

Question 2

A patient with a severe burn loses the integrity of their skin barrier. Which innate defense mechanism is most compromised?

Accepted Answer

The physical and chemical surface barriers that prevent pathogen entry.

Question 3

Which cell type is responsible for inducing apoptosis in cancer cells and virus-infected cells as part of the innate immune response?

Accepted Answer

Natural Killer cells

Question 4

During inflammation, which of the following is NOT one of the four cardinal signs?

Accepted Answer

Fever

Question 5

A patient is exposed to a virus and develops a fever. Which substance is responsible for triggering this response?

Accepted Answer

Pyrogens

Question 6

Which pathway of complement activation involves antibodies binding to pathogens and complement, forming an antigen-antibody-complement complex?

Accepted Answer

Classical pathway

Question 7

The process by which complement proteins coat pathogen surfaces to enhance phagocytosis is called:

Accepted Answer

Opsonization

Question 8

Which of the following equations best represents the splitting of complement protein C3 during activation?

Accepted Answer

$$\mathrm{C3} \rightarrow \mathrm{C3a} + \mathrm{C3b}$$

Question 9

Which of the following is a risk associated with high fever?

Accepted Answer

Denaturation of proteins

Question 10

Which statement best describes immunocompetence in lymphocytes?

Accepted Answer

Ability to recognize and bind to a specific antigen while remaining unresponsive to self-antigens.

Question 11

A patient receives an injection of antibodies after exposure to rabies. This is an example of:

Accepted Answer

Passive humoral immunity, artificially acquired

Question 12

Which immunoglobulin class is most effective at agglutinating antigens and is the first antibody released during a primary immune response?

Accepted Answer

IgM

Question 13

Which of the following best describes the structure of an antibody?

Accepted Answer

Two identical heavy chains and two identical light chains, with variable regions forming antigen-binding sites.

Question 14

A newborn receives antibodies from its mother through breast milk. This is an example of:

Accepted Answer

Passive humoral immunity, naturally acquired

Question 15

Which of the following is NOT a function of helper T cells?

Accepted Answer

Directly attacking virus-infected cells

Question 16

Which equation best represents the formation of an antigen-antibody complex?

Accepted Answer

$$	ext{Antigen} + 	ext{Antibody} ightarrow 	ext{Antigen-Antibody Complex}$$

Question 17

Which of the following best explains why cytotoxic T cells and natural killer (NK) cells are similar?

Accepted Answer

Both kill target cells by inducing apoptosis using perforins and granzymes.

Question 18

A patient with AIDS is most likely to have impaired function of which immune cell type?

Accepted Answer

Helper T cells

Question 19

Which of the following is a characteristic of autoimmune diseases?

Accepted Answer

The immune system loses the ability to distinguish self from non-self and attacks body tissues.

Question 20

A patient experiences anaphylactic shock after exposure to peanuts. Which immunoglobulin and mediator are primarily responsible?

Accepted Answer

IgE and histamine

Immune System Study Guide – Step-by-Step Guidance

Study Guide - Practice Questions