$$\text{Rate}_{\text{secondary}} \u003e \text{Rate}_{\text{primary}}$$

Question 1

Which of the following best describes the difference between innate and adaptive immunity?

Accepted Answer

Innate immunity provides immediate, non-specific defense, while adaptive immunity provides targeted, long-lasting protection after exposure.

Question 2

Which physical barrier is most directly responsible for preventing the entry of pathogens into the body?

Accepted Answer

Intact skin epidermis

Question 3

A patient develops a fever after a severe infection. Which of the following best explains the physiological benefit of fever?

Accepted Answer

Fever enhances phagocytosis and accelerates chemical reactions, speeding up tissue repair.

Question 4

Which antimicrobial protein is released in response to viral infection and signals neighboring cells to interfere with viral replication?

Accepted Answer

Interferons

Question 5

What is the primary function of the complement system in innate immunity?

Accepted Answer

To promote lysis of infected cells by forming membrane attack complexes

Question 6

Which of the following best describes how B cells recognize antigens?

Accepted Answer

B cells recognize antigens directly using Y-shaped antigen receptors with two binding sites.

Question 7

A person receives a vaccine containing inactivated bacterial toxins. What type of immunity is being induced?

Accepted Answer

Adaptive immunity (artificially acquired)

Question 8

Which of the following is TRUE regarding the secondary immune response?

Accepted Answer

It relies on memory B and T cells generated during the first exposure.

Question 9

Helper T cells are essential for activating both humoral and cell-mediated immunity. Which molecule is required for helper T cell activation?

Accepted Answer

MHC II and CD4

Question 10

Which of the following best describes the process of clonal selection?

Accepted Answer

Activated B and T cells undergo multiple divisions, producing clones that differentiate into effector and memory cells.

Question 11

A cytotoxic T cell kills an infected cell by binding to which molecule on the cell surface?

Accepted Answer

MHC I with the help of CD8

Question 12

Which of the following is a real-life example of passive immunity?

Accepted Answer

A pregnant mother transfers antibodies to her fetus via the placenta.

Question 13

Which of the following is a characteristic of autoimmune diseases?

Accepted Answer

Loss of self-tolerance, resulting in the immune system attacking the body's own cells.

Question 14

Which equation best represents the rate of antibody production during the secondary immune response compared to the primary response?

Accepted Answer

$$	ext{Rate}_{	ext{secondary}} \u003e 	ext{Rate}_{	ext{primary}}$$

Question 15

Which of the following best explains the mechanism of neutralization by antibodies?

Accepted Answer

Antibodies bind to the surface of pathogens, blocking their ability to bind to host cells.

Question 16

Which scenario best illustrates the role of mast cells in local inflammation?

Accepted Answer

Mast cells release histamine, causing capillaries to dilate and attract neutrophils to the injury site.

Question 17

Which of the following is a plausible consequence of systemic inflammation?

Accepted Answer

Release of additional neutrophils from the bone marrow and possible development of septic shock.

Question 18

Which equation best represents the relationship between antigen exposure and antibody concentration during a secondary immune response?

Accepted Answer

$$	ext{Antibody concentration}_{	ext{secondary}} \gg 	ext{Antibody concentration}_{	ext{primary}}$$

Question 19

Which of the following best describes the role of monoclonal antibodies in medicine?

Accepted Answer

Monoclonal antibodies are lab-made proteins that mimic the immune system's ability to fight infections by binding specific antigens.

The Immune System: Innate and Adaptive Defenses

Study Guide - Practice Questions