Question 1

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

Accepted Answer

Innate immunity provides immediate, non-specific defense, while adaptive immunity develops more slowly and is specific to particular pathogens.

Question 2

A patient receives a kidney transplant from a genetically unrelated donor. Which immune system component is most likely to cause rejection of the transplanted organ?

Accepted Answer

Helper T cells recognizing foreign MHC molecules on the donor tissue

Question 3

Which of the following is a correct sequence of events in the local inflammatory response?

Accepted Answer

Mast cells release histamine → Capillaries dilate → Neutrophils migrate to the site

Question 4

Which of the following best explains why Streptococcus pneumoniae can evade destruction by the innate immune system?

Accepted Answer

Its outer capsule interferes with molecular recognition and phagocytosis.

Question 5

A person is exposed to the influenza virus for the first time and develops symptoms after several days. Upon a second exposure years later, the person does not get sick. Which concept best explains this phenomenon?

Accepted Answer

Clonal selection of memory cells during the secondary immune response

Question 6

Which of the following is a function of antibodies in the humoral immune response?

Accepted Answer

Marking pathogens for inactivation or destruction

Question 7

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

Accepted Answer

TLRs recognize molecular patterns common to groups of pathogens and activate innate immune responses.

Question 8

Which of the following scenarios is an example of passive immunity?

Accepted Answer

A newborn receives IgG antibodies from the mother through the placenta.

Question 9

Which process is responsible for the immense diversity of antigen receptors on B and T cells?

Accepted Answer

Somatic recombination of V, J, and C gene segments

Question 10

A patient with a genetic defect cannot produce functional recombinase enzymes. Which aspect of their immune system would be most affected?

Accepted Answer

Ability to rearrange antigen receptor genes and generate diverse B and T cells

Question 11

Which of the following best explains why a person with AIDS is more susceptible to opportunistic infections?

Accepted Answer

HIV infects and destroys helper T cells, crippling adaptive immunity.

Question 12

Which of the following is a real-world example of antigenic variation that allows a pathogen to evade the immune system?

Accepted Answer

The parasite causing sleeping sickness switches among 1,000 versions of its surface protein.

Question 13

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

Accepted Answer

They release toxic proteins that kill infected host cells.

Question 14

A person with type 1 diabetes has an autoimmune disorder. Which of the following best describes what happens in this disease?

Accepted Answer

The immune system attacks insulin-producing cells in the pancreas.

Question 15

Which of the following is a correct statement about the complement system?

Accepted Answer

It consists of about 30 proteins that, when activated, can lead to lysis of invading cells.

Question 16

Which of the following best explains why fever can be beneficial during a systemic inflammatory response?

Accepted Answer

Fever may enhance phagocytosis and accelerate tissue repair.

Question 17

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

Accepted Answer

A person receives an injection of antibodies after a snake bite.

Question 18

Which of the following best describes the process of antigen presentation?

Accepted Answer

MHC molecules bind antigen fragments and display them on the cell surface for recognition by T cells.

Question 19

Which of the following best explains why a person with Crohn’s disease experiences chronic inflammation?

Accepted Answer

Ongoing immune responses disrupt normal intestinal function.

Chapter 43: The Immune System – Innate and Adaptive Immunity

Study Guide - Practice Questions

Study Guide - Flashcards