Question 1

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

Accepted Answer

The serum proteins referred to as complement are not induced during infection; rather, they are present in the blood innately. Their activation, however, is enhanced by the presence of invaders. Moreover, the same complement proteins are used to target many different organisms. In contrast, adaptive immunity is highly specific, involving antibodies secreted to neutralize a given pathogen. Antibodies are only needed in inducing the classical complement cascade.

Question 2

Explain the distinguishing characteristics of innate and adaptive immunity.

Accepted Answer

Innate immunity is also known as nonadaptive immunity. Innate immunity is hardwired into us and exists prior to any microbial exposure. It involves physical barriers, chemical barriers, and relatively nonspecific cellular responses to infection. Adaptive immunity is the body's reaction to specific antigens. Once the body has been activated by an antigen, it creates a memory of it such that when it encounters the same antigen again, the specific memory cells are quickly reactivated.

Question 3

Much of the ________ is normally free from microbes in a healthy individual.

Accepted Answer

A)  nose 
B)  mouth 
C)  skin 
D)  respiratory tract 
E)  genitourinary tract 
A)  nose 
B)  mouth 
C)  skin 
D)  respiratory tract 
E)  genitourinary tract E

Question 4

Detection of high levels of mannose-binding lectin in the blood could signify

Accepted Answer

A)  the presence of an invading pathogen. 
B)  ongoing virus replication. 
C)  the activation of natural killer cells. 
D)  high levels of interferons. 
E)  in-progress differentiation of leukocytes. 
A)  the presence of an invading pathogen. 
B)  ongoing virus replication. 
C)  the activation of natural killer cells. 
D)  high levels of interferons. 
E)  in-progress differentiation of leukocytes.

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

Which of the following factors contribute to dysbiosis?

Accepted Answer

A)  emotional stress 
B)  carbohydrate catabolism 
C)  probiotics 
D)  bacteriocin 
E)  anti-inflammatory cytokines 
A)  emotional stress 
B)  carbohydrate catabolism 
C)  probiotics 
D)  bacteriocin 
E)  anti-inflammatory cytokines

Question 7

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 8

Describe what is happening in the figure below.

Accepted Answer

This is a picture of periodont

Question 9

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 10

The figure below shows the ________ pathway.

Accepted Answer

A)  oxidative burst 
B)  interferon 
C)  defensins 
D)  alternative complement 
E)  complement inflammation 
A)  oxidative burst 
B)  interferon 
C)  defensins 
D)  alternative complement 
E)  complement inflammation

Question 11

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.

Question 12

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 13

Interventions that reduce a moderate fever due to infection may be counterproductive because they may

Accepted Answer

A)  produce more pyrogens. 
B)  produce prostaglandins. 
C)  induce phagocytosis. 
D)  slow recovery. 
E)  dull pain perception. 
A)  produce more pyrogens. 
B)  produce prostaglandins. 
C)  induce phagocytosis. 
D)  slow recovery. 
E)  dull pain perception.

Question 14

Are the Langerhans cells of skin-associated lymphoid tissue (SALT) related to the islets of Langerhans of the pancreas that secrete insulin? What is the function of Langerhans cells?

Accepted Answer

No, the Langerhans cells are specialized

Question 15

The hypothalamus is important because it regulates

Accepted Answer

A)  body temperature. 
B)  release of complement proteins from the liver. 
C)  neutrophil phagocytosis. 
D)  white blood cell differentiation. 
E)  pain perception. 
A)  body temperature. 
B)  release of complement proteins from the liver. 
C)  neutrophil phagocytosis. 
D)  white blood cell differentiation. 
E)  pain perception.

Question 16

Which of the following organisms is NOT a cause of chronic inflammation?

Accepted Answer

A)  a splinter 
B)  Mycobacterium tuberculosis 
C)  Mycobacterium marinum 
D)  Actinomyces bovis 
E)  biofilms on surgical implants 
A)  a splinter 
B)  Mycobacterium tuberculosis 
C)  Mycobacterium marinum 
D)  Actinomyces bovis 
E)  biofilms on surgical implants

Question 17

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 18

Describe how natural killer cells work in response to a bacterial infection.

Accepted Answer

The mission of NK cells is to kill host

Question 19

Which structure engulfs microbes by phagocytosis?

Accepted Answer

A)  hair follicle 
B)  sebaceous gland 
C)  blood vessels 
D)  sweat glands 
E)  subcutaneous tissue 
A)  hair follicle 
B)  sebaceous gland 
C)  blood vessels 
D)  sweat glands 
E)  subcutaneous tissue

Question 20

An organism responsible for tooth decay is

Accepted Answer

A)  Pseudomonas aeruginosa. 
B)  Streptococcus mutans. 
C)  Neisseria meningitides. 
D)  Streptococcus pneumoniae. 
E)  Haemophilus influenzae. 
A)  Pseudomonas aeruginosa. 
B)  Streptococcus mutans. 
C)  Neisseria meningitides. 
D)  Streptococcus pneumoniae. 
E)  Haemophilus influenzae.

Exam 23: Human Microbiota and Innate Immunity

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

Explain the distinguishing characteristics of innate and adaptive immunity.

Much of the ________ is normally free from microbes in a healthy individual.

Detection of high levels of mannose-binding lectin in the blood could signify

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

Which of the following factors contribute to dysbiosis?

Interferons are

Describe what is happening in the figure below.

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

The figure below shows the ________ pathway.

All of the following statements are correct regarding defensins EXCEPT that

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

Interventions that reduce a moderate fever due to infection may be counterproductive because they may

Are the Langerhans cells of skin-associated lymphoid tissue (SALT) related to the islets of Langerhans of the pancreas that secrete insulin? What is the function of Langerhans cells?

The hypothalamus is important because it regulates

Which of the following organisms is NOT a cause of chronic inflammation?

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

Describe how natural killer cells work in response to a bacterial infection.

Which structure engulfs microbes by phagocytosis?

An organism responsible for tooth decay is

Microbial Life: Origin and Discovery

Observing the Microbial Cell

Cell Structure and Function

Bacterial Culture, Growth, and Development

Environmental Influences and Control of Microbial Growth

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Genomes and Chromosomes

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Electron Flow in Organotrophy, Lithotrophy, and Phototrophy

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Bacterial Diversity

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Microbes in Global Elemental Cycles

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