$$\mathrm{Peptidoglycan} + \mathrm{H_2O} \xrightarrow{\text{lysozyme}} \mathrm{N-acetylglucosamine} + \mathrm{N-acetylmuramic\ acid}$$

Question 1

Which of the following best describes the role of lysozyme in innate immunity?

Accepted Answer

Lysozyme hydrolyzes the peptidoglycan layer in bacterial cell walls, leading to cell lysis.

Question 2

Which physical barrier is most effective in preventing the entry of airborne pathogens into the human body?

Accepted Answer

Mucous membranes lining the respiratory tract

Question 3

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

Accepted Answer

Increased susceptibility to bacterial infections due to reduced phagocytosis

Question 4

Which of the following is NOT a function of antimicrobial peptides in the innate immune system?

Accepted Answer

Stimulating antibody production

Question 5

Which equation correctly represents the enzymatic breakdown of peptidoglycan by lysozyme?

Accepted Answer

$$\mathrm{Peptidoglycan} + \mathrm{H_2O} \xrightarrow{	ext{lysozyme}} \mathrm{N-acetylglucosamine} + \mathrm{N-acetylmuramic\ acid}$$

Question 6

Which of the following best explains microbial antagonism in the context of the human microbiome?

Accepted Answer

Commensal microbes compete with pathogens for nutrients and space, inhibiting pathogen colonization.

Question 7

Which of the following is a chemical barrier that contributes to innate immunity?

Accepted Answer

Low pH of gastric juice in the stomach

Question 8

During the process of phagocytosis, which step involves the fusion of a phagosome with a lysosome?

Accepted Answer

Formation of the phagolysosome

Question 9

Which of the following cells are primarily responsible for nonphagocytic killing of microorganisms?

Accepted Answer

Natural killer (NK) cells

Question 10

Which of the following best describes the complement cascade?

Accepted Answer

A series of enzymatic reactions that result in the formation of a membrane attack complex, leading to lysis of pathogens.

Question 11

Which equation best represents the activation of the complement system via the classical pathway?

Accepted Answer

$$\mathrm{C1} + \mathrm{Antigen-Antibody\ Complex} \rightarrow \mathrm{C4b2a}$$

Question 12

Which of the following is a function of inflammation in the innate immune response?

Accepted Answer

To increase blood flow and recruit immune cells to the site of infection

Question 13

Which of the following best describes the role of iron-binding proteins in fighting infections?

Accepted Answer

They sequester iron, limiting its availability to pathogens and inhibiting their growth.

Question 14

Which of the following is a physical barrier that protects the body from pathogens?

Accepted Answer

Intact skin

Question 15

Which of the following best describes the process of chemotaxis during inflammation?

Accepted Answer

Movement of immune cells toward higher concentrations of chemical signals at the site of infection

Question 16

Which of the following is a correct description of the three lines of defense in the human body?

Accepted Answer

Physical and chemical barriers, innate immune cells, and adaptive immune responses

Question 17

Which of the following best explains the role of pyrogenes in fever?

Accepted Answer

Pyrogenes stimulate the hypothalamus to increase body temperature, which can inhibit pathogen growth.

Question 18

Which of the following is a correct formula for the storage of iron in the human body?

Accepted Answer

$$\mathrm{Fe$$^{3+}$$} + \mathrm{Apoferritin} \rightarrow \mathrm{Ferritin}$$

Question 19

Which of the following best describes the function of dendritic cells in innate immunity?

Accepted Answer

They act as antigen-presenting cells, bridging innate and adaptive immunity.

Question 20

Which of the following is a correct description of hematopoiesis?

Accepted Answer

The process by which all blood cells are formed from hematopoietic stem cells in the bone marrow.

Week 10 study guide

Guida di studio - Domande di pratica