Question 1

How does Propionibacterium acnes-an anaerobic Gram-positive normal flora of the skin-cause acne, especially in teenagers?

Accepted Answer

It is a normal microbial resident of the

Question 2

Interferons are

Accepted Answer

A)  antibacterial agents produced by skin, GI-tract, and lung cells. 
B)  secreted by eukaryotic cells in response to intracellular infection. 
C)  only produced by activated phagocytes. 
D)  host specific and virus specific. 
E)  able to block bacterial replication. 
A)  antibacterial agents produced by skin, GI-tract, and lung cells. 
B)  secreted by eukaryotic cells in response to intracellular infection. 
C)  only produced by activated phagocytes. 
D)  host specific and virus specific. 
E)  able to block bacterial replication.

Question 3

Why is it important for people with mitral valve prolapse to take antibiotics prior to a dental exam or procedure?

Accepted Answer

During a dental procedure, organisms tha

Question 4

Why is the alternative complement cascade not considered a part of adaptive immunity?

Accepted Answer

The serum proteins referred to as comple

Question 5

Which of the following is NOT a benefit provided by gut microbiota?

Accepted Answer

A)  inhibits inflammation 
B)  synthesis of vitamins 
C)  host tissue development 
D)  enzymes catalyze food 
E)  contributes to thin intestinal walls 
A)  inhibits inflammation 
B)  synthesis of vitamins 
C)  host tissue development 
D)  enzymes catalyze food 
E)  contributes to thin intestinal walls

Question 6

Explain the distinguishing characteristics of innate and adaptive immunity.

Accepted Answer

Innate immunity is also known as nonadap

Question 7

Why are healthy individuals usually "immune" to cholera, whereas malnourished individuals are not?

Accepted Answer

Vibrio cholerae, the causative agent of

Question 8

Defensins are short cationic peptides that

Accepted Answer

A)  are produced by skin, GI-tract, and lung cells for defense when stimulated. 
B)  bind to specific protein receptors to gain entry into microbial cells. 
C)  are only produced by phagocytes upon activation. 
D)  inhibit microbial DNA synthesis. 
E)  are equally effective at killing eukaryotic and prokaryotic cells. 
A)  are produced by skin, GI-tract, and lung cells for defense when stimulated. 
B)  bind to specific protein receptors to gain entry into microbial cells. 
C)  are only produced by phagocytes upon activation. 
D)  inhibit microbial DNA synthesis. 
E)  are equally effective at killing eukaryotic and prokaryotic cells.

Question 9

What do NK cells use to distinguish between self and nonself?

Accepted Answer

A)  platelets 
B)  MHC class I molecules 
C)  macrophages 
D)  dendritic cells 
E)  monocytes 
A)  platelets 
B)  MHC class I molecules 
C)  macrophages 
D)  dendritic cells 
E)  monocytes

Question 10

In cystic fibrosis, a mutation has rendered the receptor for binding and inactivating Pseudomonas defective. The affected gene is the CFTR. The CFTR gene product is located in the

Accepted Answer

A)  cytosol. 
B)  nucleus. 
C)  plasma membrane. 
D)  mitochondria. 
E)  phagosome. 
A)  cytosol. 
B)  nucleus. 
C)  plasma membrane. 
D)  mitochondria. 
E)  phagosome.

Question 11

How can differences in gut microbiota account for obesity and leanness in humans?

Accepted Answer

About 15%-20% of the human caloric intak

Question 12

Which of the following would NOT result in an increase in natural killer cells?

Accepted Answer

A)  internal parasite 
B)  herpes virus 
C)  Neisseria gonorrhoeae 
D)  bacterial infection 
E)  cancer 
A)  internal parasite 
B)  herpes virus 
C)  Neisseria gonorrhoeae 
D)  bacterial infection 
E)  cancer

Question 13

Interferons are

Accepted Answer

A)  high molecular weight cytokines. 
B)  not species specific. 
C)  low molecular weight cytokines. 
D)  not effective against polio virus. 
E)  not effective against influenza virus. 
A)  high molecular weight cytokines. 
B)  not species specific. 
C)  low molecular weight cytokines. 
D)  not effective against polio virus. 
E)  not effective against influenza virus.

Question 14

What factors might explain the prevalence of Gram-positive bacteria on human skin's epidermal layer?

Accepted Answer

This layer of skin has high salt secreti

Question 15

What is the biology underlying the condition of lupus? How could the symptoms of lupus be lessened on the cellular level?

Accepted Answer

Neutrophil extracellular traps, or NETs,

Question 16

Which of the following would contribute to a compromised immune system?

Accepted Answer

A)  blood pressure medication 
B)  antidepressant drugs 
C)  anticancer drugs 
D)  probiotics 
E)  vitamins 
A)  blood pressure medication 
B)  antidepressant drugs 
C)  anticancer drugs 
D)  probiotics 
E)  vitamins

Question 17

C-reactive protein is an acute-phase reactant that will bind to components of

Accepted Answer

A)  IL-1. 
B)  TNF-alpha. 
C)  bacterial cell surfaces. 
D)  host cell membranes. 
E)  cytokines. 
A)  IL-1. 
B)  TNF-alpha. 
C)  bacterial cell surfaces. 
D)  host cell membranes. 
E)  cytokines.

Question 18

Which part of the body does NOT meet the external environment?

Accepted Answer

A)  skin 
B)  mouth 
C)  gastrointestinal tract 
D)  blood 
E)  genitourinary tract 
A)  skin 
B)  mouth 
C)  gastrointestinal tract 
D)  blood 
E)  genitourinary tract

Question 19

How is it that Clostrioides difficile, often a part of the normal intestinal microflora, can be the causative agent of pseudomembranous enterocolitis?

Accepted Answer

When a person takes antibiotics, normal

Question 20

All of the following statements are correct regarding defensins EXCEPT that

Accepted Answer

A)  they are produced by skin, GI-tract, and lung cells for defense when stimulated. 
B)  they form channels that destroy bacterial cytoplasmic membranes, ultimately killing the cell. 
C)  peptides must bind the negatively charged outer membrane lipopolysacccharides. 
D)  like antibodies, they are highly specific in pathogen neutralization. 
E)  variation in defensins produced by different animals partially explains the varying susceptibility of hosts to pathogens. 
A)  they are produced by skin, GI-tract, and lung cells for defense when stimulated. 
B)  they form channels that destroy bacterial cytoplasmic membranes, ultimately killing the cell. 
C)  peptides must bind the negatively charged outer membrane lipopolysacccharides. 
D)  like antibodies, they are highly specific in pathogen neutralization. 
E)  variation in defensins produced by different animals partially explains the varying susceptibility of hosts to pathogens.

Exam 23: Human Microbiota and Innate Immunity

How does Propionibacterium acnes-an anaerobic Gram-positive normal flora of the skin-cause acne, especially in teenagers?

Interferons are

Why is it important for people with mitral valve prolapse to take antibiotics prior to a dental exam or procedure?

Why is the alternative complement cascade not considered a part of adaptive immunity?

Which of the following is NOT a benefit provided by gut microbiota?

Explain the distinguishing characteristics of innate and adaptive immunity.

Why are healthy individuals usually "immune" to cholera, whereas malnourished individuals are not?

Defensins are short cationic peptides that

What do NK cells use to distinguish between self and nonself?

In cystic fibrosis, a mutation has rendered the receptor for binding and inactivating Pseudomonas defective. The affected gene is the CFTR. The CFTR gene product is located in the

How can differences in gut microbiota account for obesity and leanness in humans?

Which of the following would NOT result in an increase in natural killer cells?

Interferons are

What factors might explain the prevalence of Gram-positive bacteria on human skin's epidermal layer?

What is the biology underlying the condition of lupus? How could the symptoms of lupus be lessened on the cellular level?

Which of the following would contribute to a compromised immune system?

C-reactive protein is an acute-phase reactant that will bind to components of

Which part of the body does NOT meet the external environment?

How is it that Clostrioides difficile, often a part of the normal intestinal microflora, can be the causative agent of pseudomembranous enterocolitis?

All of the following statements are correct regarding defensins EXCEPT that

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