Question 1

Smooth endoplasmic reticulum is involved in protein synthesis.

Accepted Answer

A) True 
 B)False

Question 2

A research laboratory is trying to produce new antibiotics. They come up with a medication that detaches the hydrophilic heads from the phospholipids in cytoplasmic membranes. This drug

Accepted Answer

A)  would be highly toxic and completely useless for human beings and could never be used-our cells also have cytoplasmic membranes with hydrophilic head groups! 
B)  would be highly toxic for human beings if taken orally, but might be useful as a topical antibiotic skin cream. The top layer of skin cells is dead anyway, so it wouldn't matter if this damaged those cells. 
C)  would be highly toxic only to bacteria, making it an excellent drug to develop and test further. Humans have a different phospholipid structure in their cytoplasmic membranes from bacteria. 
D)  would generally not be toxic enough to damage Gram-negative bacteria, as their cytoplasmic membranes lie under a thick layer of peptidoglycan. However, it would be effective against Gram-positive cells. 
E)  would not work against any bacteria, because they do not have a cytoplasmic membrane; however, it might be effective against helminths and viruses. 
A)  would be highly toxic and completely useless for human beings and could never be used-our cells also have cytoplasmic membranes with hydrophilic head groups! 
B)  would be highly toxic for human beings if taken orally, but might be useful as a topical antibiotic skin cream. The top layer of skin cells is dead anyway, so it wouldn't matter if this damaged those cells. 
C)  would be highly toxic only to bacteria, making it an excellent drug to develop and test further. Humans have a different phospholipid structure in their cytoplasmic membranes from bacteria. 
D)  would generally not be toxic enough to damage Gram-negative bacteria, as their cytoplasmic membranes lie under a thick layer of peptidoglycan. However, it would be effective against Gram-positive cells. 
E)  would not work against any bacteria, because they do not have a cytoplasmic membrane; however, it might be effective against helminths and viruses.

Question 3

A new drug is developed that inhibits formation of flagella filament by impairing production of the protein flagellin. Is this going to be an effective medication?

Accepted Answer

A)  Potentially yes-it could be used against some bacteria, but wouldn't be effective for those that don't use a flagellum to move around. 
B)  Potentially yes, but only if it could be shown that the drug also didn't impair the production of the eukaryotic flagellum. 
C)  Not at all-our eukaryotic cells depend on flagella to move around in our body, and this drug would impair that function. 
D)  Not at all-bacterial flagella are produced using microtubules, not the protein flagellin. This drug would be useless in eliminating bacteria. 
E)  Not at all-this medication would affect cells like the ciliated respiratory epithelial cells, and would cause potentially fatal side-effects. 
A)  Potentially yes-it could be used against some bacteria, but wouldn't be effective for those that don't use a flagellum to move around. 
B)  Potentially yes, but only if it could be shown that the drug also didn't impair the production of the eukaryotic flagellum. 
C)  Not at all-our eukaryotic cells depend on flagella to move around in our body, and this drug would impair that function. 
D)  Not at all-bacterial flagella are produced using microtubules, not the protein flagellin. This drug would be useless in eliminating bacteria. 
E)  Not at all-this medication would affect cells like the ciliated respiratory epithelial cells, and would cause potentially fatal side-effects.

Question 4

Prokaryotes may ingest particles via phagocytosis.

Accepted Answer

A) True 
 B)False

Question 5

Basic dyes

Accepted Answer

A)  have a negative charge. 
B)  have a positive charge. 
C)  are electrically neutral. 
D)  contain both positively and negatively charged particles. 
E)  are always blue. 
A)  have a negative charge. 
B)  have a positive charge. 
C)  are electrically neutral. 
D)  contain both positively and negatively charged particles. 
E)  are always blue.

Question 6

You discover a new pathogen which you visualize using a light microscope. A negative stain reveals a clear halo around the cells. This suggests to you that the organism

Accepted Answer

A)  is motile. 
B)  has a capsule. 
C)  is spherical in shape. 
D)  is Gram-positive. 
E)  has an LPS layer. 
A)  is motile. 
B)  has a capsule. 
C)  is spherical in shape. 
D)  is Gram-positive. 
E)  has an LPS layer.

Question 7

Lysosomes are bags of digestive enzymes found in prokaryotic cells.

Accepted Answer

A) True 
 B)False

Question 8

Cilia and flagella project from the cell and are not covered by cytoplasmic membrane.

Accepted Answer

A) True 
 B)False

Question 9

Peptidoglycan

Accepted Answer

A)  may be digested by penicillin. 
B)  consists of a long string of NAG coupled to a long string of NAM. 
C)  may be digested by lysozyme. 
D)  is found in bacteria, archaea, and plants. 
E)  is only found in Gram-positive cells. 
A)  may be digested by penicillin. 
B)  consists of a long string of NAG coupled to a long string of NAM. 
C)  may be digested by lysozyme. 
D)  is found in bacteria, archaea, and plants. 
E)  is only found in Gram-positive cells.

Question 10

You want to examine the structure of the protein coat of a virus by microscopy. Which microscope is your best choice, and why?

Accepted Answer

A)  The scanning electron microscope-it has excellent resolution and magnification (much higher than a light microscope), and can clearly visualize viruses. 
B)  An atomic force microscope-this has the highest resolution and magnification of the microscopes we discussed and we want to visualize a subcomponent of the virus particles. 
C)  A fluorescent microscope-this will let us tag the virus protein coat with colored dyes in order to visualize it using this light microscope at 1000x. 
D)  A bright-field light microscope-of course, we'll need to stain the viruses before we can visualize them against the bright white background at 1000x total magnification. 
E)  The phase-contrast microscope-it has excellent contrast and magnification, and can be used to visualize viruses very clearly. 
A)  The scanning electron microscope-it has excellent resolution and magnification (much higher than a light microscope), and can clearly visualize viruses. 
B)  An atomic force microscope-this has the highest resolution and magnification of the microscopes we discussed and we want to visualize a subcomponent of the virus particles. 
C)  A fluorescent microscope-this will let us tag the virus protein coat with colored dyes in order to visualize it using this light microscope at 1000x. 
D)  A bright-field light microscope-of course, we'll need to stain the viruses before we can visualize them against the bright white background at 1000x total magnification. 
E)  The phase-contrast microscope-it has excellent contrast and magnification, and can be used to visualize viruses very clearly.

Question 11

If everything else is equal, the best way to observe more details in a microscopic specimen is to

Accepted Answer

A)  increase resolution. 
B)  increase magnification. 
C)  increase reflection. 
D)  increase scatter. 
E)  decrease resolution. 
A)  increase resolution. 
B)  increase magnification. 
C)  increase reflection. 
D)  increase scatter. 
E)  decrease resolution.

Question 12

In viewing a microscopic specimen, oil is used to

Accepted Answer

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

Question 13

The use of oil with certain high-power objective lenses increases

Accepted Answer

A)  magnification. 
B)  reflection. 
C)  resolution. 
D)  contrast. 
E)  color. 
A)  magnification. 
B)  reflection. 
C)  resolution. 
D)  contrast. 
E)  color.

Question 14

Mitochondria and chloroplasts are thought to have once been free-living bacteria that invaded another cell.

Accepted Answer

A) True 
 B)False

Question 15

The endospore stain

Accepted Answer

A)  is applicable to many groups of bacteria. 
B)  usually shows the spores as pink structures among a background of blue 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. 
A)  is applicable to many groups of bacteria. 
B)  usually shows the spores as pink structures among a background of blue 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.

Question 16

The macromolecule found in the cell walls of all bacteria is

Accepted Answer

A)  lipid A. 
B)  teichoic acid. 
C)  peptidoglycan. 
D)  glycocalyx. 
E)  chitin. 
A)  lipid A. 
B)  teichoic acid. 
C)  peptidoglycan. 
D)  glycocalyx. 
E)  chitin.

Question 17

Facilitated diffusion and active transport

Accepted Answer

A)  both transport molecules into or out of a cell. 
B)  are both not very specific as to which molecules are transported. 
C)  both require a concentration gradient to function. 
D)  both require use of energy in order to transport the molecules. 
E)  both require a concentration gradient to function AND both require use of energy in order to transport the molecules. 
A)  both transport molecules into or out of a cell. 
B)  are both not very specific as to which molecules are transported. 
C)  both require a concentration gradient to function. 
D)  both require use of energy in order to transport the molecules. 
E)  both require a concentration gradient to function AND both require use of energy in order to transport the molecules.

Question 18

Which may result in Gram-positive bacteria appearing to be Gram-negative?

Accepted Answer

A)  Decolorizing too long AND using young cultures. 
B)  Decolorizing too short AND using young cultures. 
C)  Decolorizing too long AND using old cultures. 
D)  Decolorizing too short AND using old cultures. 
E)  Forgetting to decolorize AND using old cultures. 
A)  Decolorizing too long AND using young cultures. 
B)  Decolorizing too short AND using young cultures. 
C)  Decolorizing too long AND using old cultures. 
D)  Decolorizing too short AND using old cultures. 
E)  Forgetting to decolorize AND using old cultures.

Question 19

In a basic staining procedure, which is the correct order?

Accepted Answer

A)  Fix, smear, stain 
B)  Smear, fix, stain 
C)  Fix, stain, decolorize 
D)  Smear, decolorize, stain 
E)  Smear, stain, fix 
A)  Fix, smear, stain 
B)  Smear, fix, stain 
C)  Fix, stain, decolorize 
D)  Smear, decolorize, stain 
E)  Smear, stain, fix

Question 20

The membranes of eukaryotes and mycoplasma

Accepted Answer

A)  contain peptidoglycan. 
B)  contain sterols for strength. 
C)  contain ergosterol. 
D)  are fixed static structures. 
E)  are phospholipid unilayers. 
A)  contain peptidoglycan. 
B)  contain sterols for strength. 
C)  contain ergosterol. 
D)  are fixed static structures. 
E)  are phospholipid unilayers.

Exam 3: Microscopy and Cell Structure

Smooth endoplasmic reticulum is involved in protein synthesis.

A research laboratory is trying to produce new antibiotics. They come up with a medication that detaches the hydrophilic heads from the phospholipids in cytoplasmic membranes. This drug

A new drug is developed that inhibits formation of flagella filament by impairing production of the protein flagellin. Is this going to be an effective medication?

Prokaryotes may ingest particles via phagocytosis.

Basic dyes

You discover a new pathogen which you visualize using a light microscope. A negative stain reveals a clear halo around the cells. This suggests to you that the organism

Lysosomes are bags of digestive enzymes found in prokaryotic cells.

Cilia and flagella project from the cell and are not covered by cytoplasmic membrane.

Peptidoglycan

You want to examine the structure of the protein coat of a virus by microscopy. Which microscope is your best choice, and why?

If everything else is equal, the best way to observe more details in a microscopic specimen is to

In viewing a microscopic specimen, oil is used to

The use of oil with certain high-power objective lenses increases

Mitochondria and chloroplasts are thought to have once been free-living bacteria that invaded another cell.

The endospore stain

The macromolecule found in the cell walls of all bacteria is

Facilitated diffusion and active transport

Which may result in Gram-positive bacteria appearing to be Gram-negative?

In a basic staining procedure, which is the correct order?

The membranes of eukaryotes and mycoplasma

Humans and the Microbial World

The Molecules of Life

Dynamics of Microbial Growth

Control of Microbial Growth

Microbial Metabolism: Fueling Cell Growth

The Blueprint of Life, From Dna to Protein

Bacterial Genetics

Biotechnology

Identifying and Classifying Microorganisms

The Diversity of Bacteria and Archaea

The Eukaryotic Members of the Microbial World

Viruses, Viroids, and Prions

The Innate Immune Response

The Adaptive Immune Response

Host-Microbe Interactions

Immunological Disorders

Applications of Immune Responses

Epidemiology

Antimicrobial Medications

Respiratory System Infections

Skin Infections

Wound Infections

Digestive System Infections

Blood and Lymphatic Infections

Nervous System Infections

Genitourinary Tract Infections

Microbial Ecology

Environmental Microbiology: Treatment of Water, Wastes, and Polluted Habitats

Food Microbiology

Filters