Micro Chapter 3

25 July 2022
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question
Which of the following is NOT equal to 1mm? a) 0.001m b) 106nm c) 0.1cm d) 100Nm e) 10-3m
answer
D) 100Nm
question
What structure does light pass through after leaving the condenser in a compound light microscope? a) ocular lens b) objective lens c) specimen d) iluminator
answer
c) specimen
question
which of the following paris mismatched? a) nigrosin - negative stain b) methylene blue - simple stain c) aidic dye - capsule stain d) basic dye - negative stain e) crystal violet - simple stain
answer
d) basic dye - negative stain
question
which of the following places the step of the gram stain in the correct order? 1- Alcohol acetone 2- Crystal violet 3- Safranin 4- iodine
answer
2,4,1,3
question
Which of the following pairs is mismatched? 1) alcohol acetone - decolorizer 2) crystal violet - basic dye 3) safranin - acid dye 4) iodine - mordant 5) carbolfuchsin - basic dye
answer
3) safranin- acid dye
question
which of the following is NOT true regarding the acid fast stain? a) it is used to identify members of the genus Mycobacterium b) acid-fast cells retain the primary dye after treatment with acid alcohol c) if cells are acid-fast they are gram-negative d) acid-fast cells appear red in a completed acid-fast stain e) non-acid fast microbes appear blue in a completed acid-fast stain
answer
c) if cells are acid-fast they are gram-negative
question
The purpose of a mordant in the gram stain is to a) remove the simple stain b) make the bacterial cells larger c) make the flagella visible d) prevent the crystal violet from leaving the cells e) make gram-negative cells visib;e
answer
d) prevent the crystal violet from leaving the cells
question
which of the following places the steps in the correct sequence? 1- staining 2- making a smear 3- fixing a) 1,2,3 b) 3,2,1 c) 2,3,1 d) 1,3,2 e) the order is unimportant
answer
c) 2,3,1
question
the negative stain is used to a) visualize endospore b) determine gram reaction c) determine flagella arrangement d) visualize capsules e) determine cells size
answer
e) determine cell size
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simple staining is often necessary to improve contrast in which microscope? a) compound light microscope b) phase contrast microscope c) darkfield microscope d) fluorescence microscope e) electron microscope
answer
a) compound light microscope
question
which microscope is used to see internal structures of cells in a natural state? a) compound light microscope b) phase contrast microscope c) darkfield microscope d) fluorscence microscope e) electron microscope
answer
b) phase contras microscope
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Which microscope uses visible light? a) confocal microscope b) differential interference contrast microscope c) fluorescence microscope d) scanning acoustic microscope e) scanning electron microscope
answer
b) differential interference contrast microscope
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Which microscope achieves the highest magnification and greatest resolution? a) compound light microscope b) phase contrast microscope c) darkfield microscope d) fluorscence microscope e) electron microscope
answer
e) electron microscope
question
In using this microscope, the observer does NOT look directly at an image through a lens. a) compound light microscope b) phase contrast microscope c) darkfield microscope d) fluorscence microscope e) electron microscope
answer
e) electron microscope
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This microscope produces an image of a light cell against a dark background; internal structures are NOT visible. a) compound light microscope b) phase contrast microscope c) darkfield microscope d) fluorscence microscope e) electron microscope
answer
c) darkfield microscope
question
A virus measures 100 nm in length. what is its length in um? a) 10 um b) 1 um c) 0.1 um d) 0.01 um e) 0.001 um
answer
c) 0.1 um
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which of the following is never useful for observing living cells? a) phase contrast microscope b) darkfield microscope c) scanning acoustic microscope d) scanning electron microscope e) brightfield microscope
answer
d) scanning electron microscope
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A microorganism measures 5 μm in length. Its length in mm would be a) 500 mm b) 50 mm c) 0.5 mm d) 0.05 mm e) 0.005 mm
answer
e) 0.005mm
question
which of the following correctly traces the path of light through the compound microscope? a) light source, condenser, specimen, objective lens, ocular lens b) condenser, light source, specimen, ocular lend,objective lens c) light source, specimen , condenser, objective lens, ocular lens d) condenser, light source, specimen, objective lens, ocular lens e) light source, condenser, objective lens, specimen, ocular lens
answer
a) light source, condenser, specimen, objective lens, ocular lens
question
which microscope can be used to visualize DNA or botulium toxin? a) compound light microscope b) phase contrast microscope c) scanning tunneling microscpe d) confocal microscope e) scanning electron microscope
answer
c) scanning tunneling microscope
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Which microscope is used to observe a specimen that emits light when illuminated with an ultraviolet light? a) compound light microscope b) phase contrast microscope c) darkfield microscope d) fluorescence microscope e) electron microscope
answer
d) fluorescence microscope
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which microscope is most useful for visualizing a biofilm? a) compound light microscope b) phase contrast microscope c) fluorescence microscope d) scanning acoustic microscope e) transmission electron microscope
answer
d) scanning acoustic microscope
question
which microscope takes advantage of difference in the refractive indexes of cell structures? a) compound light microscope b) phase contrast microscope c) darkfield microscope d) fluorescence microscope e) electron microscope
answer
b) phase contrast microscope
question
you are performing a gram stain on gram positive bacteria and you stop after the addition of the first dye. what is the appearance of the bacteria at this point? a) purple b) red c) colorless d) brown
answer
a) purple
question
What structure does light pass through after leaving the condenser in a compound light microscope? A) ocular lens B) objective lens C) specimen D) illuminator
answer
c) specimen
question
Which of the following pairs is mismatched? A) nigrosin - negative stain B) methylene blue - simple stain C) acidic dye - capsule stain D) basic dye - negative stain E) crystal violet - simple stain
answer
d) basic dye- negative stain
question
Which of the following places the steps of the Gram stain in the correct order? 1-Alcohol-acetone 2-Crystal violet 3-Safranin 4-Iodine A) 1-2-3-4 B) 2-1-4-3 C) 2-4-1-3 D) 4-3-2-1 E) 1-3-2-4
answer
c) 2-4-1-3
question
Which of the following pairs is mismatched? A) alcohol-acetone — decolorizer B) crystal violet — basic dye C) safranin — acid dye D) iodine — mordant E) carbolfuchsin — basic dye
answer
c) safranin --acid dye
question
Which of the following is NOT true regarding the acid-fast stain? A) It is used to identify members of the genus Mycobacterium. B) Acid-fast cells retain the primary dye after treatment with acid-alcohol. C) If cells are acid-fast, they are gram-negative. D) Acid-fast cells appear red in a completed acid-fast stain. E) Non-acid-fast microbes appear blue in a completed acid-fast stain.
answer
C) If cells are acid-fast, they are gram-negative
question
The purpose of a mordant in the Gram stain is to A) remove the simple stain. B) make the bacterial cells larger. C) make the flagella visible. D) prevent the crystal violet from leaving the cells. E) make gram-negative cells visible
answer
d) prevent the crystal violet from leaving the cells
question
Which of the following places the steps in the correct sequence? 1-Staining 2-Making a smear 3-Fixing A) 1-2-3 B) 3-2-1 C) 2-3-1 D) 1-3-2 E) The order is unimportant.
answer
c) 2-3-1
question
The negative stain is used to A) visualize endospores. B) determine Gram reaction. C) determine flagella arrangement. D) visualize capsules. E) determine cell size.
answer
d) visualize capsule
question
Simple staining is often necessary to improve contrast in which microscope? A) compound light microscope B) phase-contrast microscope C) darkfield microscope D) fluorescence microscope E) electron microscope
answer
a) compound light microscope
question
Which microscope is used to see internal structures of cells in a natural state? A) compound light microscope B) phase-contrast microscope C) darkfield microscope D) fluorescence microscope E) electron microscope
answer
b) phase contrast microscope
question
Which microscope uses visible light? A) confocal microscope B) differential interference contrast microscope C) fluorescence microscope D) scanning acoustic microscope E) scanning electron microscope
answer
B) differential interference contrast microscope
question
Which microscope achieves the highest magnification and greatest resolution? A) compound light microscope B) phase-contrast microscope C) darkfield microscope D) fluorescence microscope E) electron microscope
answer
e) electron microscope
question
In using this microscope, the observer does NOT look directly at an image through a lens. A) compound light microscope B) phase-contrast microscope C) darkfield microscope D) fluorescence microscope E) electron microscope
answer
e) electron microscope
question
A virus measures 100 nm in length. What is its length in μm? A) 10 μm B) 1 μm C) 0.1 μm D) 0.01 μm E) 0.001 μm
answer
C) 0.1 μm
question
A microorganism measures 5 μm in length. Its length in mm would be A) 500 mm. B) 50 mm. C) 0.5 mm. D) 0.05 mm. E) 0.005 mm.
answer
E) 0.005 mm.
question
Which of the following correctly traces the path of light through the compound microscope? A) light source; condenser; specimen; objective lens; ocular lens B) condenser; light source; specimen; ocular lens; objective lens C) light source; specimen; condenser; objective lens; ocular lens D) condenser; light source; specimen; objective lens; ocular lens E) light source; condenser; objective lens; specimen; ocular lens
answer
A) light source; condenser; specimen; objective lens; ocular lens
question
Which microscope is most useful for visualizing a biofilm? A) compound light microscope B) phase-contrast microscope C) fluorescence microscope D) scanning acoustic microscope E) transmission electron microscope
answer
d) scanning acoustic microscope
question
You are performing a Gram stain on gram-positive bacteria and you stop after the addition of the first dye. What is the appearance of the bacteria at this point? A) purple B) red C) colorless D) brown
answer
A) purple
question
You are performing a Gram stain on gram-negative bacteria and you stop after the addition of the mordant. What is the appearance of the bacteria at this point? A) purple B) red C) colorless D) brown
answer
A) purple
question
You are performing a Gram stain on gram-negative bacteria and you stop after the decolorizer step. What is the appearance of the bacteria at this point? A) purple B) red C) colorless D) brown
answer
c) colorless
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You are performing a Gram stain on gram-positive bacteria and you stop after the addition of the counterstain. What is the appearance of the bacteria at this point? A) purple B) red C) colorless D) brown
answer
a) purple
question
Which type of stain is most useful in helping clinicians to decide which antibiotic to prescribe for a bacterial infection? A) negative stain B) simple stain C) Gram stain D) endospore stain E) flagella stain
answer
C) gram stain
question
What is the total magnification of a specimen viewed with a 10x ocular lens and a 45x objective lens? A) 4.5x B) 10x C) 45x D) 100x E) 450x
answer
E) 450x
question
Which microscope is used to see detail of a 300-nm virus? A) fluorescence microscope B) phase-contrast microscope C) darkfield microscope D) DIC microscope E) electron microscope
answer
e) electron microscope
question
Which step in the Gram stain is the critical step in differentiating gram-positive cells from gram-negative cells? A) safranin B) alcohol-acetone C) iodine D) crystal violet
answer
b) alcohol acetone
question
Which microscope is best used for observing the surfaces of intact cells and viruses? A) phase-contrast microscope B) darkfield microscope C) fluorescence microscope D) brightfield microscope E) scanning electron microscope
answer
e) scanning electron microscope
question
Bacterial smears are fixed before staining to A) affix the cells to the slide. B) make their walls permeable. C) accept stain. D) make the cells visible
answer
a) affix the cells to the slide
question
A student is looking at a bacterial specimen using the oil immersion lens, but has forgotten to put immersion oil on the slide. The specimen will appear A) smaller than it would if immersion oil was used. B) larger than it would if immersion oil was used. C) somewhat fuzzy and have poor resolution. D) the same as it would if the immersion oil was used. E) to have no color.
answer
C) somewhat fuzzy and have poor resolution.
question
The purpose of the ocular lens is to A) improve resolution. B) magnify the image from the objective lens. C) decrease the refractive index. D) increase the light. E) decrease the light.
answer
B) magnify the image from the objective lens.
question
In microscopy, the term resolution A) refers to the ability to distinguish fine structure and detail in a specimen. B) is the same as the total magnification of a specimen. C) is improved when longer wavelengths of light are employed. D) is only observed in stained specimens. E) refers to magnification when using the electron microscope.
answer
A) refers to the ability to distinguish fine structure and detail in a specimen.
question
Acid fast mycobacteria differ from nonacid fast bacteria by the presence of ____. A) capsules B) flagella C) peptidoglycan D) endospores E) waxy material in their cell wall
answer
E) waxy material in their cell wall
question
All of the following are true for both TEM and SEM except A) the specimen must be sectioned before viewing B) the microscope if focused using electromagnetic lenses C) the illuminating souce is an electron beam D) both can be used to view specimens smaller than 0.2 micrometers E) black ans white images are produced
answer
A) the specimen must be sectioned before viewing
question
In a negative staining procedure, the bacterial cells would be ___. A) unstained in a unstained background B) the same color as the background and thus not easily observed C) attracted to the dye used in the staining procedure D) brightly colored in a contrasting background E) unstained in a colored background
answer
A) unstained in a unstained background
question
The capsules stained using India ink, capsules are distinguished as ___ surrounding cells A) clear halos B) purple rims C) blue extensions D) green shadows E) pink circles
answer
A) clear halos
question
In a gram stain, crystal violet is the ___. A) decolorizing agent B) fixative C) counterstain D) mordant E) primary stain
answer
E) primary stain
question
In the gram stain, crystal violet remains in gram positive cells after treatment with alcohol because crystal violet iodine (cv-1) complexes are trapped ___. A) in thick layers of peptidoglycan B) in the outer membrane C) by endoscopes D) in mycolic acid E) by flagella
answer
A) in thick layers of peptidoglycan
question
In the gram stain, if the decolorizing step is deleted, gram negative cells will appear ___ at the completion of the staining procedure. A) unstained B) purple C) green D) pink E) blue
answer
B) purple
question
In the gram stain procedure, a clear oval in the center of a cell could indicate ___. A) lack of a central nucleoid B) the unstained bacterial chromosome C) presence of a endospore D) capsule E) an unstained nucleus
answer
C) presence of a endospore
question
The ___ charge of a basic dye adheres to the ___ charge of bacterial cell surfaces. A) positive; negative B) positive; basic C) negative; positive D) positive; acidic E) negative; acidic
answer
A) positive; negative
question
Which is common to the gram stain and acid fast stain A) use of iodine as a mordant B) use of acid alcohol for decolorizing C) use of methylene blue as a counter stain D) use of stream for stain penetration E) fixation of the smear before staining
answer
E) fixation of the smear before staining
question
Which of the following kinds of microscopy would be most appropriate for viewing the shape and arrangement of pili or fimbriae on the surface of a bacterial cell A) transmission electron microscopy B) phase contrast microscopy C) darkfield microscopy D) brightfield microscopy E) scanning electron microscopy
answer
E) scanning electron microscopy
question
Which of the following types of microscopy can be used to specifically identify pathogens (such as mycobacterium tuberculosis or rabies virus) in specimens A) phase contrast B) fluorescence C) transmission electron D) darkfield E) brightfield
answer
B) fluorescence
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Which of the following types of microscopy is most useful for viewing the internal structures of unstained specimens A) confocal B) fluorescence C) phase contrast D) electron E) brightfield
answer
C) phase contrast
question
Which of the following types of microscopy is used to study the structure of the slimy accumulation of bacteria on a IV catheter tip A) atomic force B) phase contrast C) confocal D) scanning acoustic E) scanning electron
answer
D) scanning acoustic
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Which type of light microscopy is used to visualize stained specimens A) compound B) binocular C) brightfield D) phase contrast E) darkfield
answer
C) brightfield
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Which type of microscope uses a metal and diamond probe that is gently forced down along the surface of a specimen A) atomic force B) transmission electron C) confocal D) scanning tunneling
answer
A) atomic force
question
You are viewing a sputum smear that has been stained with an acid fast stain. On this smear you see 5 um long red cells. You can conclude that ___. A) the normal microbiota are acid fast B) human cells are acid fast C) there are acid fast bacteria in the specimen D) there are no acid fast bacteria in the specimen E) the normal microbiota are gram positive
answer
C) there are acid fast bacteria in the specimen
question
Your lab partner tells you the bacteria are moving in this gram stained smear. You can conclude that ___. A) the bacteria are chemotatic B) he didn't fix the smear C) the bacteria are gram negative D) the bacteria have capsules E) he did a flagella stain, not a gram stain
answer
B) he didn't fix the smear