Question 1

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

Accepted Answer

Innate immunity is present at birth and responds rapidly, while adaptive immunity develops over time and is specific to pathogens.

Question 2

Which of the following is a chemical factor contributing to the body's first line of defense?

Accepted Answer

Sebum produced by sebaceous glands

Question 3

A patient presents with a fever after a bacterial infection. Which of the following best explains the physiological mechanism behind fever?

Accepted Answer

Pyrogens stimulate the hypothalamus to increase the body's temperature set point.

Question 4

Which of the following leukocytes is primarily responsible for combating parasitic infections?

Accepted Answer

Eosinophils

Question 5

During phagocytosis, which step involves the fusion of a phagosome with a lysosome?

Accepted Answer

Formation of the phagolysosome

Question 6

Which of the following best describes the role of normal microbiota in innate immunity?

Accepted Answer

They compete with pathogens for nutrients and space, a process known as competitive inhibition.

Question 7

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

Accepted Answer

Lysozyme in tears

Question 8

A patient is exposed to a virus and develops immunity after recovering. Which type of acquired immunity is this?

Accepted Answer

Naturally acquired active immunity

Question 9

Which immunoglobulin is most abundant in serum and is the only one that can cross the placenta?

Accepted Answer

Ig G

Question 10

Which of the following best describes the function of cytotoxic T cells?

Accepted Answer

They directly kill infected cells by recognizing antigens presented on MHC I molecules.

Question 11

Which process is illustrated by the equation $$	ext{Antigen} + 	ext{Antibody} ightarrow 	ext{Agglutination}$$?

Accepted Answer

Agglutination

Question 12

A newborn receives antibodies from its mother through breast milk. Which immunoglobulin is primarily involved?

Accepted Answer

Ig A

Question 13

Which of the following best describes the role of Toll-like receptors (TLRs) in innate immunity?

Accepted Answer

They recognize pathogen-associated molecular patterns (PAMPs) and activate immune responses.

Question 14

Which of the following is a correct sequence of events in phagocytosis?

Accepted Answer

Chemotaxis \rightarrow Adherence \rightarrow Ingestion \rightarrow Formation of phagolysosome \rightarrow Digestion \rightarrow Exocytosis

Question 15

Which antibody class is primarily responsible for allergic reactions and defense against parasitic worms?

Accepted Answer

Ig E

Question 16

Which of the following is a function of helper T cells?

Accepted Answer

They secrete cytokines that activate B cells and cytotoxic T cells.

Question 17

Which of the following best describes the outcome of opsonization?

Accepted Answer

Antibodies coat pathogens, enhancing their uptake by phagocytes.

Question 18

A patient receives an injection of antivenom after a snake bite. Which type of immunity is this?

Accepted Answer

Artificially acquired passive immunity

Question 19

Which of the following best explains why the secondary immune response is faster and stronger than the primary response?

Accepted Answer

Memory cells generated during the primary response recognize the antigen and mount a rapid response.

Question 20

Which of the following is a real-world example of neutralization by antibodies?

Accepted Answer

Antibodies bind to tetanus toxin, preventing it from attaching to nerve cells.

Innate and Adaptive Immunity: Study Notes

Study Guide - Practice Questions