Question 1

Which of the following best describes the primary difference between innate immunity and adaptive (acquired) immunity?

Accepted Answer

Innate immunity provides a rapid, non-specific response, whereas adaptive immunity develops more slowly and is highly specific to particular pathogens.

Question 2

Keratin, found in the outer layer of skin, contributes to the first line of defense by:

Accepted Answer

Forming a tough, waterproof barrier that resists microbial invasion.

Question 3

Which of the following best describes the function of the ciliary escalator in the respiratory tract?

Accepted Answer

It moves mucus and trapped microbes upward toward the throat to be expelled or swallowed.

Question 4

Sebum, a chemical factor in innate immunity, helps prevent infection by:

Accepted Answer

Lowering the pH of the skin, creating an environment hostile to many microbes.

Question 5

Which of the following is NOT a mechanical method for removing microbes from the body?

Accepted Answer

Production of interferons

Question 6

During phagocytosis, which step immediately follows the attachment of the phagocyte to the microbe?

Accepted Answer

Ingestion of the microbe by the phagocyte

Question 7

Which of the following best defines opsonization?

Accepted Answer

The coating of a microbe with molecules that enhance its ingestion and destruction by phagocytes.

Question 8

A patient presents with a fever after a bacterial infection. Which of the following is a physiological advantage of fever in this context?

Accepted Answer

Fever enhances the activity of some immune cells and inhibits the growth of some pathogens.

Question 9

Which of the following is a potential disadvantage of fever?

Accepted Answer

It can denature host enzymes and cause tissue damage at high temperatures.

Question 10

Which of the following blood cells is primarily responsible for the early response to bacterial infection and is the most abundant type of leukocyte?

Accepted Answer

Neutrophils

Question 11

Which pathway of the complement system is initiated by antibodies binding to antigens?

Accepted Answer

Classical pathway

Question 12

Which of the following is NOT a result of complement system activation?

Accepted Answer

Interferon production

Question 13

A bacterial pathogen evades the complement system by producing a capsule. This strategy is effective because:

Accepted Answer

The capsule prevents the binding of complement proteins to the bacterial surface.

Question 14

Interferons protect neighboring cells from viral infection by:

Accepted Answer

Inducing the production of antiviral proteins in uninfected cells.

Question 15

Which of the following best describes the process of hematopoiesis?

Accepted Answer

The formation and development of blood cells from stem cells in the bone marrow.

Question 16

A patient with a parasitic worm infection is likely to have an increased number of which type of white blood cell?

Accepted Answer

Eosinophils

Question 17

Which of the following is a correct sequence of events during inflammation?

Accepted Answer

Vasodilation → Phagocyte migration → Tissue repair

Question 18

The hypothalamus is involved in fever by:

Accepted Answer

Acting as the body's thermostat and raising the set point in response to pyrogens.

Question 19

A patient is unable to produce lysozyme in their tears. Which of the following would most likely result?

Accepted Answer

Increased susceptibility to bacterial eye infections due to reduced breakdown of peptidoglycan.

Question 20

A multi-step scenario: A patient with a skin wound is exposed to a bacterial pathogen. The bacteria are coated with complement proteins, and neutrophils are recruited to the site. Which of the following best describes the sequence of immune responses involved?

Accepted Answer

First line of defense (skin barrier) → Complement activation (opsonization) → Phagocytosis by neutrophils

Microbiology Exam 4 Study Guide – Immunity, Defense Mechanisms, and Blood Components

Study Guide - Practice Questions

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