Question 1

The cell wall of Gram-negative organisms

Accepted Answer

A)   has a thick peptidoglycan layer.
B)   has a thin peptidoglycan layer.
C)   is more permeable to various molecules than the Gram-positive cell wall.
D)   is characterized by an outer membrane containing LPS.
E)   has a thin peptidoglycan layer AND is characterized by an outer membrane containing LPS.F) C) and D)
G) A) and D)

Question 2

The nucleus

Accepted Answer

A)   is a double membrane sac containing DNA and is found in eukaryotes.
B)   is a single phospholipid membrane sac containing prokaryotic DNA.
C)   is a smaller structure contained within the eukaryotic nucleolus.
D)   cannot transport molecules to the cytoplasm due to the double membrane barrier.E) A) and C)
F) C) and D)

Question 3

Drugs that target prokaryotic protein synthesis would have no effect on eukaryotic protein synthesis.

Accepted Answer

A) True 
 B)False

Question 4

Penicillin would be most effective against

Accepted Answer

A)   non-growing bacteria.
B)   growing bacteria.
C)   Gram-positive bacteria.
D)   Gram-negative bacteria.
E)   growing bacteria AND Gram-positive bacteria.F) A) and B)
G) A) and C)

Question 5

Which of the following microscope types would be least useful in viewing unstained living cells?

Accepted Answer

A)   phase contrast
B)   interference
C)   bright-field
D)   dark-fieldE) None of the above
F) A) and B)

Question 6

In viewing a microscopic specimen, oil is used to

Accepted Answer

A)   increase the refraction.
B)   decrease the refraction.
C)   increase the reflection.
D)   increase the resolution.
E)   decrease the refraction AND increase the resolution.F) B) and D)
G) A) and C)

Question 7

Bacillus and Clostridium are medically relevant groups of bacteria that characteristically stain acid-fast.

Accepted Answer

A) True 
 B)False

Question 8

An electron microscope must place the specimen in a vacuum within a sealed chamber. Why?

Accepted Answer

A)   Electrons are particles-there are also particles in air. Without a vacuum, the electrons would strike and be scattered by the atoms/particles within the air.
B)   Because electrons are highly radioactive, and the chamber must be completely sealed to prevent them from escaping and contaminating the lab area.
C)   This is the method for fixing the specimen to the slide grid for an electron microscope. Without fixing the specimen by vacuum, it would slide off and we wouldn't be able to visualize it.
D)   All of the above are true.E) A) and B)
F) B) and C)

Question 9

The Gram stain and the endospore stain both use

Accepted Answer

A)   basic dyes.
B)   acidic dyes.
C)   safranin.
D)   methylene blue.
E)   basic dyes AND safranin.F) B) and C)
G) A) and C)

Question 10

Another new drug is developed-this one inhibits formation of the flagellar filament by impairing production of the protein flagellin. Is this going to be a good drug?

Accepted Answer

A)   Potentially-it would definitely only impair bacteria, but wouldn't matter for the ones that don't use a flagellum to move around.
B)   Potentially-if it could be shown that it also didn't impair the production of the eukaryotic flagellum.
C)   No-our eukaryotic cells depend on flagella to move around in our body, and this would impair that function.
D)   No-bacterial flagella are produced using microtubules, not the protein flagellin. This drug would be useless in eliminating bacteria.E) B) and C)
F) None of the above

Question 11

The cytoplasmic membrane of both eukaryotes and prokaryotes functions to

Accepted Answer

A)   form endoplasmic reticulum.
B)   produce energy.
C)   regulate movement of molecules which enter and leave the cell.
D)   form lysosomes and golgi apparatus.E) None of the above
F) A) and B)

Question 12

Immunofluorescence

Accepted Answer

A)   uses fluorescently tagged molecules.
B)   makes use of the specificity in binding of antibodies.
C)   utilizes acridine orange.
D)   would require a special UV microscope.
E)   uses fluorescently tagged molecules, makes use of the specificity in binding of antibodies AND would require a special UV microscope.F) All of the above
G) A) and C)

Question 13

Electron microscopes differ from light microscopes in that

Accepted Answer

A)   electrons replace light.
B)   electromagnets replace glass lenses.
C)   resolution is higher.
D)   magnification is higher.
E)   All of the choices are correct.F) None of the above
G) A) and E)

Question 14

The capsule

Accepted Answer

A)   may be used for protection.
B)   may be used to help the bacteria adhere to surfaces.
C)   may be involved in movement.
D)   may be involved in energy production.
E)   may be used for protection AND may be used to help the bacteria adhere to surfaces.F) A) and B)
G) C) and D)

Question 15

Which is not true of the cytoplasmic membrane?

Accepted Answer

A)   It defines the boundaries of the cell.
B)   It is a semipermeable barrier.
C)   It consists mainly of a fixed, static phospholipid bilayer.
D)   It uses proteins as selective gates and sensors.
E)   All of the choices are true.F) A) and B)
G) A) and C)

Question 16

Phagocytosis

Accepted Answer

A)   is the ingestion of particles and may be performed by animal cells.
B)   is the ingestion of particles and may be performed by bacteria.
C)   is the secretion of proteins.
D)   is the formation of a lysosome.
E)   is the ingestion of particles and may be performed by bacteria AND is the formation of a lysosome.F) B) and E)
G) All of the above

Question 17

Your instructor wants you to bring in an example of a biofilm to your lab. Which choice is the best selection for bringing in an intact biofilm for further study?

Accepted Answer

A)   Disconnecting and bringing in the old, mildewed showerhead from the showers in your dorm.
B)   Scraping the mold off of the shower curtain in your dorm's bathroom into a paper cup using a butter knife.
C)   Using a toothpick to scrape plaque off of your teeth and smearing it onto a slide to bring in to lab.
D)   Wiping a sponge across a slimy boulder in a stream in a nearby park and bringing it in to lab.E) B) and C)
F) C) and D)

Question 18

The endospore stain

Accepted Answer

A)   is applicable to only a few groups of bacteria.
B)   usually shows the spores as green structures among a background of pink cells.
C)   uses crystal violet as the primary stain.
D)   is an example of a negative stain.
E)   is applicable to only a few groups of bacteria AND usually shows the spores as green structures among a background of pink cells.F) C) and D)
G) None of the above

Question 19

LPS is found in the outer membrane of Gram-positive bacteria.

Accepted Answer

A) True 
 B)False

Question 20

Specimens can be observed at the atomic level using a(n)

Accepted Answer

A)   scanning electron microscope.
B)   transmission electron microscope.
C)   atomic force microscope.
D)   All of the choices are correct.
E)   None of the choices is correct.F) A) and C)
G) A) and E)

Exam 3: Microscopy and Cell Structure

Bacillus and Clostridium are medically relevant groups of bacteria that characteristically stain acid-fast.

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Which is not true of the cytoplasmic membrane?

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The cell wall of Gram-negative organisms

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The endospore stain

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LPS is found in the outer membrane of Gram-positive bacteria.

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The nucleus

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The cytoplasmic membrane of both eukaryotes and prokaryotes functions to

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In viewing a microscopic specimen, oil is used to

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Immunofluorescence

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Specimens can be observed at the atomic level using a(n)

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Another new drug is developed-this one inhibits formation of the flagellar filament by impairing production of the protein flagellin. Is this going to be a good drug?

Correct AnswerverifiedShow Answer

The capsule

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An electron microscope must place the specimen in a vacuum within a sealed chamber. Why?

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Which of the following microscope types would be least useful in viewing unstained living cells?

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Drugs that target prokaryotic protein synthesis would have no effect on eukaryotic protein synthesis.

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Electron microscopes differ from light microscopes in that

Correct AnswerverifiedShow Answer

The Gram stain and the endospore stain both use

Correct AnswerverifiedShow Answer

Phagocytosis

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Penicillin would be most effective against

Correct AnswerverifiedShow Answer

Your instructor wants you to bring in an example of a biofilm to your lab. Which choice is the best selection for bringing in an intact biofilm for further study?

Correct AnswerverifiedShow Answer

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