Question 1

Which of the following best describes the body's first line of defense against pathogens?

Accepted Answer

Physical and chemical barriers such as skin and mucous membranes

Question 2

Keratin is a protein found in the skin. What is its primary function in body defense?

Accepted Answer

It forms a tough, waterproof barrier preventing pathogen entry

Question 3

Which chemical produced by epithelial membranes is most effective at breaking down bacterial cell walls?

Accepted Answer

Lysozyme

Question 4

Cilia in the mucosa of the upper respiratory tract help defend the body by:

Accepted Answer

Sweeping trapped particles and pathogens out of the airways

Question 5

Which of the following is NOT part of the body's second line of defense?

Accepted Answer

Antibody production

Question 6

Phagocytosis is best described as:

Accepted Answer

The process by which cells engulf and digest pathogens

Question 7

Macrophages originate from which precursor cell?

Accepted Answer

Monocyte

Question 8

Natural killer (NK) cells are unique because they:

Accepted Answer

Directly attack virus-infected and cancerous cells without prior sensitization

Question 9

Which of the following is a benefit of inflammation?

Accepted Answer

It increases blood flow, bringing immune cells and nutrients to the site of injury

Question 10

The four cardinal signs of inflammation include redness, heat, swelling, and pain. Which of the following causes swelling?

Accepted Answer

Increased capillary permeability leading to fluid leakage into tissues

Question 11

Interferons are secreted by cells infected with viruses. What is their primary function?

Accepted Answer

They signal neighboring cells to produce antiviral proteins

Question 12

Complement proteins are found in the blood plasma. How many types are there?

Accepted Answer

Many

Question 13

Which of the following best describes the action of complement proteins?

Accepted Answer

They form a membrane attack complex that lyses pathogens

Question 14

Humoral immunity differs from cell-mediated immunity in that humoral immunity:

Accepted Answer

Is mediated by antibodies produced by B cells

Question 15

Antigenic determinants are:

Accepted Answer

Specific regions of an antigen recognized by antibodies

Question 16

When an antigen is 'presented,' what does this mean?

Accepted Answer

A cell displays fragments of the antigen on its surface for recognition by T cells

Question 17

Most B cells become plasma cells after activation. What is the function of plasma cells?

Accepted Answer

They secrete large amounts of antibodies

Question 18

If a B cell does not become a plasma cell, it becomes a memory cell. What is the function of memory cells?

Accepted Answer

They provide a rapid response upon subsequent exposure to the same antigen

Question 19

Which antibody class is released first during a primary immune response?

Accepted Answer

IgM

Question 20

Which type of T cell acts as the 'director' of the immune response?

Accepted Answer

Helper T cell

Step-by-Step Guidance for Body Defenses (ANP Immunology)

Study Guide - Practice Questions