Question 1

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

Accepted Answer

Innate immunity is present at birth and acts rapidly, while adaptive immunity is slower and has memory.

Question 2

Which of the following is NOT a physical factor involved in the first line of defense against pathogens?

Accepted Answer

Lysozyme in tears

Question 3

A patient with a genetic defect in Toll-like receptors (TLRs) would most likely have difficulty with which aspect of immunity?

Accepted Answer

Recognizing pathogen-associated molecular patterns (PAMPs)

Question 4

Which of the following best explains why normal microbiota are important for innate immunity?

Accepted Answer

They compete with pathogens for resources and produce substances harmful to pathogens.

Question 5

Which chemical factor in the first line of defense is responsible for breaking bonds in peptidoglycan, thus destroying bacterial cell walls?

Accepted Answer

Lysozyme

Question 6

A patient is taking a broad-spectrum antibiotic and develops a gastrointestinal infection with Salmonella. Which concept best explains this occurrence?

Accepted Answer

The antibiotic disrupted normal microbiota, reducing microbial antagonism.

Question 7

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

Accepted Answer

They regulate the intensity and duration of immune responses.

Question 8

Which of the following white blood cells is primarily responsible for releasing histamine during allergic responses?

Accepted Answer

Basophils

Question 9

Which process describes the coating of a microorganism with serum proteins to enhance phagocytosis?

Accepted Answer

Opsonization

Question 10

A patient infected with Mycobacterium tuberculosis is found to have bacteria surviving inside phagolysosomes. Which microbial strategy is being used?

Accepted Answer

Surviving in phagolysosome

Question 11

Which of the following is NOT a sign or symptom of inflammation?

Accepted Answer

Fever

Question 12

Which of the following best describes the role of the lymphatic system in immunity?

Accepted Answer

It filters blood plasma and returns it to the circulatory system, allowing lymphocytes and macrophages to destroy pathogens.

Question 13

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

Accepted Answer

Chemotaxis → Adherence → Ingestion → Digestion

Question 14

Which of the following is a real-life example of microbial antagonism provided by normal microbiota?

Accepted Answer

E. coli in the colon produces bacteriocins that inhibit Salmonella and Shigella.

Question 15

Which of the following best explains why the skin is an effective barrier to microbial invasion?

Accepted Answer

It is dry, salty, acidic, and undergoes constant exfoliation.

Question 16

Which of the following is a function of eosinophils?

Accepted Answer

Toxic action against parasites and helminths

Question 17

A patient with a deficiency in lysozyme production would be most susceptible to infections in which of the following body fluids?

Accepted Answer

Tears and saliva

Question 18

Which of the following is a correct statement about probiotics?

Accepted Answer

They are live microbial cultures that provide health benefits to the host.

Question 19

Which of the following is a chemical factor that inhibits microbial growth in the vaginal tract?

Accepted Answer

Low pH (acidic environment)

Question 20

A patient is infected with Shigella, which is able to escape from the phagosome before digestion. Which step of phagocytosis is being evaded?

Accepted Answer

Digestion

Innate Immunity: The Body’s First and Second Lines of Defense

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