MCB 100 EXAM 2 I CLICKER QUESTIONS AND
ACCURATE ANSWERS
What is the basis for assigning organisms into the three different domains of life
(Bacteria, Archaea, and Eukarya)?
A.DNA structure and location
B. Presence of flagella
C. Method of reproduction
D.Type of staining used to see them
E. rRNA gene sequences - Answers - E. rRNA gene sequences
The bacterial arrangement illustrated here is known as ____
A. a chain of bacilli.
B. palisades.
C. pleomorphic group.
D. a tetrad.
E. a cluster of cocci. - Answers - A. a chain of bacilli.
Biofilm formation begins with _______ A. cells maturing and dividing.
B. a slimy polysaccharide matrix being secreted.
C. extracellular polymer substances clumping.
D. free-floating cells attaching to a surface.
E. a bunch of cells clustering together. - Answers - D. free-floating cells attaching to a
surface.
Which of the following statements about biofilms is TRUE?
A. In a single-species biofilm, the interior environment is uniform throughout.
B. The environment of the biofilm matrix is not conducive to uptake of colored dyes.
C. Biofilms cannot continue to grow at low nutrient concentrations.
D. In biofilms there is often metabolic cooperation among bacteria.
E. In biofilms all the bacteria are living, but those that die are released into the medium.
- Answers - D. In biofilms there is often metabolic cooperation among bacteria.
Biofilms can be found benefiting our bodies _______
A. in the intestinal tract.
B. in the mouth.
C. on contact lenses.
D. on replacement joints.
E. in the lung trachea. - Answers - A. in the intestinal tract.
Which of the culture tubes below contains flagellated bacteria? - Answers - A- The
foggy tube
, Which of the following capillaries contains no stimulant? - Answers - B- some inside the
tube and some outside in the container
Why do doctors caution patients who are pregnant to avoid deli meats, cold cuts, and
soft cheeses? A. Fermentation of those food by Listeria will cause nausea.
B. The Listeria bacteria can make these foods taste sour.
C. These foods are used by the Listeria bacteria to make neurotoxins.
D. The Listeria bacteria can grow in them when stored in the refrigerator.
E. The Listeria bacteria can degrade the nutrients in the food. - Answers - D. The
Listeria bacteria can grow in them when stored in the refrigerator.
Which of the following statements about Gram-positive Listeria is TRUE?
A. They produce powerful toxins that lyse eukaryotic cells.
B. They form resistant endospores that can withstand harsh chemical environments.
C. They can invade and live within cells to avoid the host's immune system.
D. They move rapidly through the body using multiple flagella called comet tails.
E. They resist most antimicrobial agents due to biofilm formation. - Answers - C. They
can invade and live within cells to avoid the host's immune system.
Gram-negative bacteria can attach to surfaces via their _________ .
A. fimbriae.
B. flagella.
C. peptidoglycan.
D. comet tails.
E. porins. - Answers - A. fimbriae.
A strain of the Gram-negative bacterium Vibrio cholerae, which causes the diarrheal
disease cholera, has a mutation that has caused the bacterium to lose the ability to
produce fimbriae and so it has become less virulent as a consequence. What function
has this pathogen lost?
A. The ability to move from one location in the body to another.
B. The ability to produce and release cholera toxin.
C. The ability to grow inside the host's intestine.
D. The ability to escape the phagosome and enter the cytosol. E. The ability to adhere
to a host cell. - Answers - E. The ability to adhere to a host cell.
Pathogenic strains of Gram-positive Staphylococcus aureus can spread along tissue
planes to cause blistering by producing and secreting _______
A. a protease called staphylokinase.
B. a protease called exfoliative toxin.
C. a DNA-degrading nuclease (DNase). D.an RNA-degrading nuclease (RNase).
E. a pore-forming toxin called staphylolysin. - Answers - B. a protease called exfoliative
toxin.
ACCURATE ANSWERS
What is the basis for assigning organisms into the three different domains of life
(Bacteria, Archaea, and Eukarya)?
A.DNA structure and location
B. Presence of flagella
C. Method of reproduction
D.Type of staining used to see them
E. rRNA gene sequences - Answers - E. rRNA gene sequences
The bacterial arrangement illustrated here is known as ____
A. a chain of bacilli.
B. palisades.
C. pleomorphic group.
D. a tetrad.
E. a cluster of cocci. - Answers - A. a chain of bacilli.
Biofilm formation begins with _______ A. cells maturing and dividing.
B. a slimy polysaccharide matrix being secreted.
C. extracellular polymer substances clumping.
D. free-floating cells attaching to a surface.
E. a bunch of cells clustering together. - Answers - D. free-floating cells attaching to a
surface.
Which of the following statements about biofilms is TRUE?
A. In a single-species biofilm, the interior environment is uniform throughout.
B. The environment of the biofilm matrix is not conducive to uptake of colored dyes.
C. Biofilms cannot continue to grow at low nutrient concentrations.
D. In biofilms there is often metabolic cooperation among bacteria.
E. In biofilms all the bacteria are living, but those that die are released into the medium.
- Answers - D. In biofilms there is often metabolic cooperation among bacteria.
Biofilms can be found benefiting our bodies _______
A. in the intestinal tract.
B. in the mouth.
C. on contact lenses.
D. on replacement joints.
E. in the lung trachea. - Answers - A. in the intestinal tract.
Which of the culture tubes below contains flagellated bacteria? - Answers - A- The
foggy tube
, Which of the following capillaries contains no stimulant? - Answers - B- some inside the
tube and some outside in the container
Why do doctors caution patients who are pregnant to avoid deli meats, cold cuts, and
soft cheeses? A. Fermentation of those food by Listeria will cause nausea.
B. The Listeria bacteria can make these foods taste sour.
C. These foods are used by the Listeria bacteria to make neurotoxins.
D. The Listeria bacteria can grow in them when stored in the refrigerator.
E. The Listeria bacteria can degrade the nutrients in the food. - Answers - D. The
Listeria bacteria can grow in them when stored in the refrigerator.
Which of the following statements about Gram-positive Listeria is TRUE?
A. They produce powerful toxins that lyse eukaryotic cells.
B. They form resistant endospores that can withstand harsh chemical environments.
C. They can invade and live within cells to avoid the host's immune system.
D. They move rapidly through the body using multiple flagella called comet tails.
E. They resist most antimicrobial agents due to biofilm formation. - Answers - C. They
can invade and live within cells to avoid the host's immune system.
Gram-negative bacteria can attach to surfaces via their _________ .
A. fimbriae.
B. flagella.
C. peptidoglycan.
D. comet tails.
E. porins. - Answers - A. fimbriae.
A strain of the Gram-negative bacterium Vibrio cholerae, which causes the diarrheal
disease cholera, has a mutation that has caused the bacterium to lose the ability to
produce fimbriae and so it has become less virulent as a consequence. What function
has this pathogen lost?
A. The ability to move from one location in the body to another.
B. The ability to produce and release cholera toxin.
C. The ability to grow inside the host's intestine.
D. The ability to escape the phagosome and enter the cytosol. E. The ability to adhere
to a host cell. - Answers - E. The ability to adhere to a host cell.
Pathogenic strains of Gram-positive Staphylococcus aureus can spread along tissue
planes to cause blistering by producing and secreting _______
A. a protease called staphylokinase.
B. a protease called exfoliative toxin.
C. a DNA-degrading nuclease (DNase). D.an RNA-degrading nuclease (RNase).
E. a pore-forming toxin called staphylolysin. - Answers - B. a protease called exfoliative
toxin.
