Question 1

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

Accepted Answer

Innate immunity is always present and acts non-specifically, while adaptive immunity develops specific responses after exposure to a pathogen.

Question 2

Which of the following is NOT a component of the first line of defense in innate immunity?

Accepted Answer

Antibodies

Question 3

A patient is infected with a novel virus. Which immune response will act first to contain the infection?

Accepted Answer

Innate immunity through physical barriers and phagocytes

Question 4

Which of the following best explains why the adaptive immune response is faster and more effective upon a second exposure to the same pathogen?

Accepted Answer

Memory cells generated during the first exposure rapidly proliferate and respond.

Question 5

Which of the following is a function of the complement system?

Accepted Answer

Opsonization, formation of membrane attack complex (MAC), and induction of inflammation

Question 6

What is the role of pattern-recognition receptors (PRRs) in the innate immune system?

Accepted Answer

They recognize pathogen-associated molecular patterns (PAMPs) and activate phagocytes.

Question 7

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

Accepted Answer

Lipopolysaccharide (LPS)

Question 8

During inflammation, which molecule is primarily responsible for vasodilation and increased blood vessel permeability?

Accepted Answer

Histamine

Question 9

Which of the following best describes the process of opsonization?

Accepted Answer

The process by which antibodies or complement proteins coat pathogens to enhance phagocytosis.

Question 10

Which class of MHC molecule presents antigens derived from cytoplasmic proteins and is found on all nucleated cells?

Accepted Answer

MHC-I

Question 11

A child receives antibodies from her mother through breast milk. This is an example of:

Accepted Answer

Passive natural immunity

Question 12

Which of the following best describes the role of lymph nodes in the immune response?

Accepted Answer

They are sites where antigens and immune cells interact, activating adaptive immunity.

Question 13

Which of the following is a cellular component of the innate immune system?

Accepted Answer

Neutrophils

Question 14

How does lysozyme kill bacteria?

Accepted Answer

By disrupting the bacterial cell wall through hydrolysis of peptidoglycan

Question 15

Which of the following best explains why activated phagocytes increase the expression of enzymes that produce free radicals?

Accepted Answer

To kill the phagocytized pathogen more effectively

Question 16

Which of the following is a non-cellular component of the adaptive immune system?

Accepted Answer

Antibodies

Question 17

Which process allows phagocytes to move from the bloodstream into infected tissues?

Accepted Answer

Diapedesis

Question 18

Which of the following best describes the function of cytokines during an immune response?

Accepted Answer

They are signaling molecules that coordinate the actions of immune cells.

Question 19

Which of the following is a correct sequence of events during the immune response to a bacterial infection?

Accepted Answer

Pathogen entry → Innate immune response → Antigen presentation → Adaptive immune response

Question 20

Which of the following best describes the role of the ciliated epithelium in the respiratory tract?

Accepted Answer

It traps and moves pathogens out of the respiratory tract through coordinated ciliary movement.

Innate and Adaptive Immunity: Structure and Function in Immunology

Study Guide - Practice Questions