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 highly specific.

Question 2

Which of the following is NOT a function of the skin in the first line of defense?

Accepted Answer

Secretes antibodies to neutralize pathogens.

Question 3

Which of the following is a correct pairing of a physical and chemical defense mechanism?

Accepted Answer

Cilia movement and lysozyme secretion

Question 4

Which of the following best describes the role of MHC class I molecules?

Accepted Answer

They present endogenous antigens to CD8+ T cells.

Question 5

A patient receives a vaccine containing inactivated virus particles. Which type of immunity is being induced?

Accepted Answer

Artificial active immunity

Question 6

Which of the following is a PAMP (Pathogen-Associated Molecular Pattern)?

Accepted Answer

Lipopolysaccharide (LPS) from Gram-negative bacteria

Question 7

Which of the following best explains why memory B cells respond more rapidly upon second exposure to an antigen?

Accepted Answer

They have higher affinity receptors due to somatic hypermutation.

Question 8

Which of the following equations correctly represents the relationship between antigen-antibody binding and affinity?

Accepted Answer

$$K_d = \frac{[Ag][Ab]}{[AgAb]}$$

Question 9

Which of the following is a correct statement about the process of phagocytosis?

Accepted Answer

Phagocytes ingest pathogens and present antigens via MHC class II molecules.

Question 10

A patient with a genetic defect in the complement system is most likely to experience which of the following?

Accepted Answer

Increased susceptibility to bacterial infections

Question 11

Which of the following best describes the function of cytotoxic T cells (CD8+)?

Accepted Answer

They kill infected host cells by recognizing antigen presented on MHC class I molecules.

Question 12

Which of the following is a characteristic of a good immunogen?

Accepted Answer

High molecular weight and complex structure

Question 13

Which of the following best explains why live attenuated vaccines often provide longer-lasting immunity than inactivated vaccines?

Accepted Answer

They replicate in the host, stimulating a stronger and more diverse immune response.

Question 14

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

Accepted Answer

Vasodilation → Increased vascular permeability → Migration of phagocytes → Tissue repair

Question 15

Which of the following best describes the role of helper T cells (CD4+)?

Accepted Answer

They secrete cytokines that activate other immune cells.

Question 16

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

Accepted Answer

Receiving antivenom after a snake bite

Question 17

Which of the following best explains why antigenic variation in pathogens can make vaccine development challenging?

Accepted Answer

Pathogens change their surface proteins, evading immune recognition.

Question 18

Which of the following best describes the process of clonal selection in B cells?

Accepted Answer

Only B cells with receptors specific to an antigen proliferate and differentiate into plasma cells.

Question 19

Which of the following is a correct statement about the role of dendritic cells in the immune response?

Accepted Answer

They capture antigens and present them to T cells, initiating adaptive immunity.

Question 20

Which of the following best explains why booster shots are sometimes necessary for vaccines?

Accepted Answer

They increase the number of memory cells and prolong immunity.

Microbiology Final Exam Study Guide: Immunity, Adaptive Defenses, and Food Microbiology

Study Guide - Practice Questions