Chapter 3 MIcroscopy and Cell Structure Flashcards
Eukaryotic cells are
A. less complex than prokaryotic cells.
B. members of the domains Bacteria and Archaea.
C. defined by the presence of a membrane bound nucleus.
D. able to reproduce more rapidly than prokaryotes.
E. less complex than prokaryotic cells, members of the domains Bacteria and Archaea AND able to reproduce more rapidly than prokaryotes.
C. defined by the presence of a membrane bound nucleus.
The two magnifying lenses found in a light microscope are the
A. basic and transverse.
B. small and large.
C. ocular and objective.
D. simple and phase.
C. ocular and objective.
The resolving power of a microscope is described as the ability of the microscope to
A. separate clearly two objects that are very close together.
B. magnify an object.
C. separate the colors of an organism’s internal structure.
D. see structures at various depths in a tissue.
A. separate clearly two objects that are very close together.
In viewing a microscopic specimen, oil is used to
A. increase the refraction.
B. decrease the refraction.
C. increase the reflection.
D. increase the resolution.
E. decrease the refraction AND increase the resolution.
E. decrease the refraction AND increase the resolution.
The use of oil with certain high power objective lenses increases
A. magnification.
B. the amount of light that enters the objective lens.
C. resolution.
D. contrast.
E. All of the choices are correct.
B. the amount of light that enters the objective lens.
If everything else is equal, the best way to observe more details in a microscopic specimen is to
A. increase resolution.
B. increase magnification.
A. increase resolution.
The microscope which allows the specimen to appear 3-dimensional is the
A. phase contrast microscope.
B. interference microscope.
C. fluorescence microscope.
D. dark-field microscope.
B. interference microscope.
Which of the following microscope types would be least useful in viewing unstained living cells?
A. phase contrast
B. interference
C. bright-field
D. dark-field
C. bright-field
Electron microscopes differ from light microscopes in that
A. electrons replace light.
B. electromagnets replace glass lenses.
C. resolution is higher.
D. magnification is higher.
E. All of the choices are correct.
E. All of the choices are correct.
Specimens can be observed at the atomic level using a(n)
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.
C. atomic force microscope.
Individual atoms on the surface of prepared samples can be observed by using the
A. phase contrast microscope.
B. scanning electron microscope.
C. dark-field microscope.
D. atomic force microscope.
D. atomic force microscope.
Basic dyes
A. have negative charges.
B. have positive charges.
C. are electrically neutral.
D. contain both positively and negatively charged particles.
B. have positive charges.
Which of the following stains is/are considered differential?
A. capsule stain.
B. flagella stain.
C. acid-fast stain.
D. Gram stain.
E. acid-fast stain AND Gram stain.
E. acid-fast stain AND Gram stain.
The Gram stain and the endospore stain both use
A. basic dyes.
B. acidic dyes.
C. safranin.
D. methylene blue.
E. basic dyes AND safranin.
E. basic dyes AND safranin
The order of reagents in the Gram stain reaction are
A. safranin, alcohol, methylene blue, iodine.
B. crystal violet, iodine, alcohol, safranin.
C. methylene blue, alcohol, safranin.
D. crystal violet, alcohol, iodine, safranin.
B. crystal violet, iodine, alcohol, safranin.
Which may result in Gram-positive bacteria appearing to be Gram-negative?
A. decolorizing too long
B. decolorizing too short
C. using old cultures
D. using young cultures
E. decolorizing too long AND using old cultures
E. decolorizing too long AND using old cultures
The major criteria used in placing bacteria into different groups is based on differences in
A. cell wall structure.
B. cell membrane permeability.
C. presence or absence of flagella.
D. detergent susceptibility.
A. cell wall structure.
In a basic staining procedure, which is the correct order?
A. fix, smear, stain
B. smear, fix, stain
C. fix, stain, decolorize
D. smear, decolorize, stain
B. smear, fix, stain
The acid-fast stain
A. reflects differences in cytoplasmic membrane structure.
B. is useful for distinguishing a small group of organisms, including Mycobacterium.
C. uses crystal violet and safranin.
D. uses carbolfuchsin and methylene blue.
E. is useful for distinguishing a small group of organisms, including Mycobacterium AND uses carbolfuchsin and methylene blue.
E. is useful for distinguishing a small group of organisms, including Mycobacterium AND uses carbolfuchsin and methylene blue.
Capsules
A. take up stain well.
B. may correlate with an organism’s ability to cause disease.
C. are typically “negatively” stained.
D. are stained as a wet mount.
E. may correlate with an organism’s ability to cause disease, are typically “negatively” stained AND are stained as a wet mount.
E. may correlate with an organism’s ability to cause disease, are typically “negatively” stained AND are stained as a wet mount.
The endospore stain
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.
E. is applicable to only a few groups of bacteria AND usually shows the spores as green structures among a background of pink cells.
Which fluorescent stain would be useful for distinguishing between dead and living bacteria?
A. acridine orange
B. auramine
C. rhodamine
D. CTC
D. CTC
Immunofluorescence
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.
E. uses fluorescently tagged molecules, makes use of the specificity in binding of antibodies AND would require a special UV microscope.
Which term(s) refer(s) to bacterial morphology?
A. Bacillus
B. coccus
C. bacillus
D. polyhedral
E. coccus AND bacillus
E. coccus AND bacillus
Which is not true of the cytoplasmic membrane?
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.
C. It consists mainly of a fixed, static phospholipid bilayer.
Which is true of simple diffusion of water?
A. Water usually enters a cell and produces a tremendous osmotic pressure.
B. Water usually leaves the cell and produces negative osmotic pressure.
C. Water tends to enter and leave the cell equally, resulting in no pressure in the cell.
D. The diffusion ultimately relies on the selectively permeable nature of the cell membrane.
E. Water usually enters a cell and produces a tremendous osmotic pressure AND the diffusion ultimately relies on the selectively permeable nature of the cell membrane.
E. Water usually enters a cell and produces a tremendous osmotic pressure AND the diffusion ultimately relies on the selectively permeable nature of the cell membrane.
The cytoplasmic membrane of both eukaryotes and prokaryotes functions to
A. form endoplasmic reticulum.
B. produce energy.
C. regulate movement of molecules which enter and leave the cell.
D. form lysosomes and golgi apparatus.
C. regulate movement of molecules which enter and leave the cell.
The proteins of bacteria that are involved in the movement of small molecules into the cell, are called
A. transport proteins.
B. permeases.
C. carriers.
D. peptidases.
E. transport proteins, permeases AND carriers.
E. transport proteins, permeases AND carriers.
Most solutes pass through the cytoplasmic membrane via
A. osmosis.
B. diffusion.
C. transport proteins.
D. secretion.
C. transport proteins.
Facilitated diffusion and active transport
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 an expenditure of energy in order to transport the molecules.
E. both require a concentration gradient to function AND both require an expenditure of energy in order to transport the molecules.
A. both transport molecules into or out of a cell.
The macromolecule found in the cell walls of all bacteria is
A. diaminopimelic acid.
B. teichoic acid.
C. peptidoglycan.
D. glycocalyx.
C. peptidoglycan.
Which is(are) true concerning the cell wall of prokaryotes?
A. It determines the shape of the bacteria.
B. It prevents the bacteria from bursting.
C. It contains peptidoglycan.
D. It may be targeted by antimicrobials.
E. All of the choices are true.
E. All of the choices are true.
Which amino acid(s) is/are found only in the cell walls of bacteria?
A. glycerol
B. L-form of glycine
C. diaminopimelic acid
D. L-form of methionine
E. L-form of glycine AND L-form of methionine
C. diaminopimelic acid
The cell wall of Gram-positive bacteria
A. contains a thin layer of peptidoglycan.
B. contains a thick layer of peptidoglycan.
C. is, due to its thickness, an excellent barrier to most molecules.
D. contains an outer membrane containing LPS.
E. contains a thin layer of peptidoglycan AND contains an outer membrane containing LPS.
B. contains a thick layer of peptidoglycan.
Which molecules are associated with the cell wall of Gram-positive bacteria?
A. peptidoglycan
B. D-form amino acids
C. teichoic acids
D. LPS
E. peptidoglycan, D-form amino acids AND teichoic acids
E. peptidoglycan, D-form amino acids AND teichoic acids
The cell wall of Gram-negative organisms
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.
E. has a thin peptidoglycan layer AND is characterized by an outer membrane containing LPS.
Endotoxin
A. consists of LPS.
B. determines bacterial shape.
C. may have different effects depending on the specific bacterial source.
D. is toxic due to the effects of the peptide side chains.
E. determines bacterial shape, may have different effects depending on the specific bacterial source AND is toxic due to the effects of the peptide side chains.
A. consists of LPS.
