Question 1

Which of the following best describes the function of cilia and mucus in the respiratory tract as shown in the provided images?

Accepted Answer

They trap and remove inhaled particles and pathogens from the airway.

Question 2

Which of the following is a correct statement about the human microbiome based on the study materials and images?

Accepted Answer

The microbiome consists of bacteria, fungi, and viruses that compete with pathogens and help train the immune system.

Question 3

Which of the following is NOT a function of the complement system as shown in the provided diagrams?

Accepted Answer

Directly producing antibodies against pathogens

Question 4

A patient has a genetic defect that prevents the formation of perforin. Which immune process would be most directly impaired?

Accepted Answer

Killing of virus-infected cells by NK cells and cytotoxic T cells

Question 5

Which of the following best explains why cytotoxic T cells do not attack healthy cells?

Accepted Answer

Healthy cells display self-antigens on MHC-I molecules, which are recognized as 'self' by cytotoxic T cells.

Question 6

Which of the following is a key difference between the classical and alternative pathways of complement activation?

Accepted Answer

The classical pathway is activated by antigen-antibody complexes, while the alternative pathway is activated by spontaneous hydrolysis of C3.

Question 7

A person receives a vaccine and later is exposed to the same pathogen. Which graph best represents the antibody response upon second exposure?

Accepted Answer

A graph showing a rapid, high-magnitude antibody response (secondary response)

Question 8

Which of the following best describes the role of pattern recognition receptors (PRRs) on phagocytes?

Accepted Answer

They recognize pathogen-associated molecular patterns (PAMPs) to trigger phagocytosis.

Question 9

Which of the following is a function of lysozyme as described in the study materials?

Accepted Answer

It is an enzyme that attacks bacterial cell walls.

Question 10

Which of the following best explains why the adaptive immune response is considered antigen-specific and generates memory?

Accepted Answer

It involves clonal expansion of lymphocytes specific to the encountered antigen and produces memory cells for faster future responses.

Question 11

Which of the following best describes the process of opsonization?

Accepted Answer

Antibodies or complement proteins coat pathogens, enhancing their recognition and ingestion by phagocytes.

Question 12

A patient with a deficiency in MHC class II molecules would have the most difficulty with which of the following immune functions?

Accepted Answer

Activation of helper T cells

Question 13

Which of the following is a correct statement about the four cardinal signs of inflammation described by Aulus Cornelius Celsus?

Accepted Answer

Redness is due to increased blood flow from vasodilation.

Question 14

Which of the following best explains the 'missing self' hypothesis for NK cell activation?

Accepted Answer

NK cells are activated when target cells lack or have reduced MHC-I expression, indicating infection or transformation.

Question 15

Which of the following is a function of helper T cells (CD4+)?

Accepted Answer

Activating B cells and cytotoxic T cells by releasing cytokines

Question 16

Which of the following best describes the structure of an antibody as shown in the images?

Accepted Answer

It consists of two heavy chains and two light chains forming a Y-shaped molecule.

Question 17

Which of the following best explains the difference between primary and secondary immune responses?

Accepted Answer

The secondary response is faster and produces more antibodies due to memory cells.

Question 18

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

Accepted Answer

A person receives antibodies from their mother through breast milk.

Question 19

Which of the following best describes the role of regulatory T cells (Tregs)?

Accepted Answer

They suppress immune responses to prevent excessive reactions and autoimmunity.

Question 20

Which of the following best explains why vaccines are effective in preventing infectious diseases?

Accepted Answer

They induce a primary immune response, leading to the formation of memory cells that provide rapid and robust protection upon future exposure.

The Immune System: Lines of Defense and Immune Responses

Study Guide - Practice Questions