Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
15 Cards in this Set
- Front
- Back
|
1) Which of the following statements best describes the human intestinal microbiota?
a) The species present in the microbiota can be very different in different people, but similar biochemical functions are provided by the microbiota regardless of the species present b) The species present in the microbiota are very similar in different people and the microbiota provides a similar set of biochemical functions to the host c) The species present in the microbiota can be very different in different people and the biochemical functions provided by the microbiota are also highly variable between individual people |
A
|
|
|
2) Experiments performed with germ-free and ex-germ-free mice have shown that intestinal bacteria:
a) Provide vitamins to the host b) Allow the host to obtain energy from carbohydrates that the host can’t catabolize c) Increase nutrient uptake from the intestine d) All of the above e) None of the above |
D
|
|
|
3) Compared to conventionally-raised mice, germ-free mice:
a) Gain more weight after ingesting the same amount of food b) Have fewer B cells associated with the Peyer’s patches c) Have more capillaries in the intestinal villi d) All of the above e) None of the above |
B
|
|
|
4) In most people, the majority of the bacterial species colonizing the intestine belong to one of two phyla, which are the:
a) Bacteroidetes and Fungi b) Firmicutes and Fungi c) Bacteroidetes and Euryarchaeota d) Firmicutes and Bacteroidetes e) Bacteroidetes and Cyanobacteria |
D
|
|
|
5) Which, if any, of these parts of the human body are normally colonized by microorganisms?
a) Teeth b) Skin c) Stomach d) All of the above e) None of the above |
D
|
|
|
6) What is the source of toxicity of endotoxins?
a) Endotoxins cause T cells to secrete cytokines, which leads to toxic shock b) Endotoxins lyse red blood cells c) Endotoxins block protein synthesis in host cells d) Endotoxins cause septic shock e) Endotoxins produce a life-threatening increase in blood pressure |
D
|
|
|
7) Which of the following is an endotoxin?
a) Peptidoglycan b) Aflatoxin c) Cholera toxin d) All of the above e) None of the above |
A
|
|
|
8) Some bacterial pathogens can manipulate a host cell to reorganize its cytoskeleton by injecting bacterial effector proteins into the cytoplasm of the eukaryotic cell.
a) True b) False |
A
|
|
|
10) What distinguishes endotoxins from exotoxins?
a) Endotoxins are enzymes that act in the cytoplasm of host cells b) Endotoxins bind to host cells and trigger endocytosis c) Exotoxins act only at the surface of host cells, while endotoxins may function both outside and inside of host cells d) Endotoxins are secondary metabolites e) Endotoxins are structural components of bacterial or fungal cells |
E
|
|
|
9) This toxin protein causes intoxicated host cells to continuously export Cl- ions, which leads to diarrhea and dehydration.
a) Diphtheria toxin b) Tetanus toxin c) Cholera toxin d) Aflatoxins e) Botulinum toxin |
C
|
|
|
11) Antimicrobial peptides are used by some white blood cells to help kill pathogens. What is the basis of their antimicrobial activity?
a) Disrupting the plasma membranes of pathogens b) Degrading peptidoglycan c) Binding to bacterial ribosomes and blocking protein synthesis d) Binding to pathogens and promoting phagocytosis e) Generating superoxide and other reactive oxygen species |
A
|
|
|
12) How do phagocytic white blood cells recognize pathogens?
a) Receptors on phagocytic cells bind to molecules, such as peptidoglycan or B-1,3-glucan, that are shared by many pathogens b) Receptors on phagocytic cells bind to antibodies that are bound to a pathogen c) Receptors on phagotyctic cells bind to complement proteins that are bound to a pathogen d) All of the above e) None of the above |
D
|
|
|
13) Phagocytic cells that are found in healthy tissues
a) Macrophages b) Neutrophils c) T-helper cells d) Cytotoxic T cells e) B cells |
A
|
|
|
14) White blood cells that kill virus-infected host cells
a) Macrophages b) Neutrophils c) T-helper cells d) Cytotoxic T cells e) B cells |
D
|
|
|
15) White blood cells that synthesize antibodies
a) Macrophages b) Neutrophils c) T-helper cells d) Cytotoxic T cells e) B cells |
E
|
