Question 1

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

Accepted Answer

Innate immunity provides immediate, non-specific defense, while adaptive immunity develops specific responses and memory over time.

Question 2

According to the hygiene hypothesis, what is the proposed effect of decreased diversity in normal microbiota on immune responses?

Accepted Answer

It may negatively affect immune responses, leading to increased susceptibility to immune-related disorders.

Question 3

Which of the following is an example of a mechanical barrier in the first line of innate defense?

Accepted Answer

Tears washing debris from the eye

Question 4

Which of the following best explains why the skin is an effective physical barrier against pathogens?

Accepted Answer

It is composed of a layer of dead epithelial cells, proteins, and lipids that are water-resistant.

Question 5

Which of the following is a function of antimicrobial peptides (AMPs) in innate immunity?

Accepted Answer

They insert into microbial membranes, causing cell lysis.

Question 6

What is the primary role of the lymphatic system in immune defense?

Accepted Answer

To collect, circulate, and filter fluid (lymph) for the removal of waste, pathogens, and toxins before returning it to the blood.

Question 7

Which of the following best describes the process of phagocytosis by neutrophils?

Accepted Answer

Neutrophils engulf pathogens, fuse the phagosome with a lysosome, and destroy the contents with hydrolytic enzymes.

Question 8

Which of the following is a key function of cytokines in the innate immune response?

Accepted Answer

They act as signaling proteins to coordinate immune cell communication and recruit leukocytes to infection sites.

Question 9

During the inflammatory response, what is the main effect of vasoactive molecules released in the vascular changes phase?

Accepted Answer

They increase vessel permeability and dilation, leading to redness and heat.

Question 10

Which of the following statements about fever is correct?

Accepted Answer

Fever is induced by pyrogens, which signal the hypothalamus to raise the body's temperature set point.

Question 11

Which of the following is a distinguishing feature of adaptive immunity compared to innate immunity?

Accepted Answer

It generates immunological memory and tailors responses to specific antigens.

Question 12

What is the main function of memory cells in adaptive immunity?

Accepted Answer

To rapidly mount a strong immune response upon re-exposure to the same antigen.

Question 13

Which of the following best describes the role of Major Histocompatibility Complex (MHC) molecules in adaptive immunity?

Accepted Answer

They present antigen fragments on cell surfaces for recognition by T cells.

Question 14

Which of the following is a correct sequence of the four general stages of adaptive immune response?

Accepted Answer

Antigen presentation, lymphocyte activation, lymphocyte proliferation and differentiation, antigen elimination and memory

Question 15

Which of the following best describes the difference between T-dependent and T-independent B cell activation?

Accepted Answer

T-dependent activation requires help from T helper cells, while T-independent activation does not.

Question 16

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

Accepted Answer

IgM

Question 17

Which of the following is an example of artificially acquired passive immunity?

Accepted Answer

Receiving an injection of antitoxin after a snake bite

Question 18

Which of the following best describes the role of opsonization in immune defense?

Accepted Answer

It is the tagging of pathogens by antibodies or complement proteins to enhance phagocytosis.

Question 19

Which of the following is a potential consequence of chronic inflammation?

Accepted Answer

Exacerbation of tissue injury and promotion of diseases such as atherosclerosis and certain cancers

Question 20

A patient receives a vaccine and later produces high-affinity IgG antibodies upon re-exposure to the same pathogen. Which type of adaptive immunity is this an example of?

Accepted Answer

Artificially acquired active immunity

Innate and Adaptive Immunity: Principles and Mechanisms (Chapters 11 & 12)

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