Question 1

Which of the following best describes the primary goal of first-line defenses in the immune system?

Accepted Answer

To prevent pathogen entry into the body

Question 2

Leukocytes are central to second-line defenses because they:

Accepted Answer

Directly kill invaders and coordinate inflammation

Question 3

In the classical pathway of complement activation, what triggers the cascade?

Accepted Answer

Binding of antibodies to antigens

Question 4

Which of the following is NOT one of the three main outcomes of complement activation?

Accepted Answer

Antibody production

Question 5

A phagocytic cell engulfs its target in a vesicle called a phagosome. What happens next?

Accepted Answer

The phagosome fuses with a lysosome containing hydrolytic enzymes

Question 6

If an individual is born with a genetic disorder preventing the production of hydrolytic enzymes, what is the most likely consequence?

Accepted Answer

Phagocytosis will occur, but pathogens will not be effectively degraded

Question 7

Which of the following is a key difference between innate and adaptive immunity?

Accepted Answer

Adaptive immunity remembers antigens and amplifies responses upon later exposure

Question 8

Which cell is the key effector of the cellular branch of adaptive immunity?

Accepted Answer

Cytotoxic T cell

Question 9

Helper T cells (TH) are essential in the adaptive immune response because they:

Accepted Answer

Coordinate and regulate the activation of B cells and cytotoxic T cells

Question 10

Which of the following best describes the difference between effector cells and memory cells?

Accepted Answer

Effector cells act immediately to fight infection, while memory cells remain long-term and respond faster upon re-exposure

Question 11

Which proteins are released by effector cytotoxic T cells to kill target cells?

Accepted Answer

Perforin and granzymes

Question 12

How do perforin and granzymes work together to kill a target cell?

Accepted Answer

Perforin forms pores in the target cell membrane, allowing granzymes to enter and trigger apoptosis

Question 13

During the humoral response, activated B cells differentiate into plasma cells and memory B cells. Which is the effector cell?

Accepted Answer

Plasma cell

Question 14

Which of the following is NOT a key function of antibodies?

Accepted Answer

Phagocytosis

Question 15

Which antibody class is produced first during a primary immune response?

Accepted Answer

IgM

Question 16

What is the main advantage of actively acquired immunity compared to passively acquired immunity?

Accepted Answer

It confers long-lasting protection due to memory cell formation

Question 17

Why are booster doses necessary for inactivated vaccines?

Accepted Answer

Because inactivated vaccines do not elicit a strong memory response and require reinforcement

Question 18

Which vaccine formulation is considered safer for immunocompromised individuals, and why?

Accepted Answer

Inactivated vaccine, because it contains no live organism to cause potential harm

Question 19

Herd immunity protects nonimmunized people primarily by:

Accepted Answer

Reducing the spread of disease when a large portion of the population is immunized

Question 20

A patient receives antibodies against a pathogen through a medical treatment. Which category of adaptive immunity does this represent?

Accepted Answer

Artificially acquired passive immunity

Innate and Adaptive Immunity: Study Guide (Chapters 11, 12, 14)

Study Guide - Practice Questions