micro lab quizzes
what three characteristics of your isolates can yoiu determine using SIM medium
S = sulfur reduction (black growth) I = indole production (red indicator) M = motility (growth along/extending from stab line)
what is the name of the enzyme that can convert the substrate ONPG into yellow colored products a) beta galactosidase b) glucuronidase c) cytochrome c oxidase d) succinate dehydrogenase
a) beta galactosidase
the algal group whcih has a characteristic cell wall made of silica (glass) and comes in a variety of beautiful shapes and sizes is _________ a) diatoms b) coccolithophores c) cyanobacteria d) dinoflagellates
a) diatoms
a fungus that has both mold and yeast life cycle stages is called a ________ fungi a) dimorphic b) macro c) septate d) pathogenic
a) dimorphic
one purpose of a streak plate is to a) obtain isolation of individual species from a mixed sample b) observe the behavior of the micorbe c) provide for extensive growth of a mixed culture d) allow for quantification of colony forming units
a) obtain isolation of individual species from a mixed sample
a tube of milk that turns white in less than 1 hour in a methylene blue reductase test is considered a) poor quality b) medium quality c) good quality d) high quality
a) poor quality
for bacterial transformation, the bacterial cells must be competent. what does this mean? a) the cells undergo changes that allow them to take up foreign DNA b) the cell wall is removed to allow DNA to enter the cell c) the chromosomal DNA is removed to make room for the plasmid DNA d) the cells become very smart
a) the cells undergo changes that allow them to take up foreign DNA
what is the genus name of the bacteria we worked with in the transformation lab and why did we use this genus
acinetobacter because it is naturally always competent to taking up DNA
after incubation of the tube, is there anything else that needs to be done to complete the SIM test if so, what would be a positive result
addition of kovacs reagent a positive result after addition of kovacs reagent would be presence of red color
what is the penalty for the second violation of the safety policy
administratively dropped from course
the ability or inability of a microorganism to live in the presence of oxygen is called _________
aerotolerance
the term __________ technique refers to handling sterile materials or known cultures without contaminating them
aseptic
in the last class period, the media we prepared was sterilized by placing it in the __________ (name of equipment) at 121℃
autoclave
which of the following groups of microalgae is unique in that it contains calcium carbonate in its cell wall a) diatoms b) coccolithophores c) cyanobacteria d) dinoflagellates
b) coccolithophores
which enzyme can breakdown MUG to produce fluorescent blue color under UV light a) beta galactosidase b) glucuronidase c) cytochrome c oxidase d) succinate dehydrogenase
b) glucuronidase
a single fungal filament is called a ________ a) mycelium b) hypha c) macrofungi d) sporangium
b) hypha
although fluid thioglycollate medium allows for the growth of microbes in all aerotolerance categories, it is more commonly used for the growth of anaerobes and microaerophiles because: a) it contains the proper nutrients for these organisms b) it contains ingredients that prevent oxygen from becoming equally diffused throughout the whole tube c) the amount of CO2 in the tube is very high d) the amount of agar in the tube is very low
b) it contains ingredients that prevent oxygen from becoming equally diffused throughout the whole tube
TSY + streptomycin plate sectors were b) susceptible cells c) resistant cells d) susceptible cells + DNA e) susceptible cells + DNase + DNA which sector(s) did we expect no growth
b) susceptible cells -- because these cells were originally susceptible to streptomycin and were not changed, therefore they could not grow in this media e) susceptible cells + DNase + DNA -- because the DNase destroyed the streptomycin resistant DNA, therefore leaving this sector with only streptomycin susceptible cells
the actively moving and feeding stage of a protozoan's life cycle is called the _________ stage a) spore b) trophozoite c) cyst d) flagellar
b) trophozoite
a tube of milk that turns white in less than 30 mins in a methylene blue reductase test is considered a) poor quality b) very poor quality c) good quality d) high quality
b) very poor quality
you perform a transformation experiment to try and make susceptible cells become rsistant. you take resistant cells, lyse them with SDS to release the DNA, then heat them to kill any remaining cells. you then plate the following cells in different sectors: a - DNA b- susceptible cells c- resistant cells d- susceptible cells + DNA (resistant) e- susceptible cells + DNAse + DNA (resistant) which sectors would you expect growth to occur
b- susceptible cells c- resistant cells d- susceptible cells + DNA (resistant) e- susceptible cells + DNAse + DNA (resistant)
in te methylene blue reductase test (MBRT), the dye methylene blue will have a _____ color when it is in the oxidized state, and will turn ______ when it is reduced
blue (oxidized) clear/white (reduced)
why must the methylene blue reductase test (MBRT) be performed in a sealed tube a) the gas produced must be collected b) to prevent contamination c) because oxygen will disrupt the ability to observe the results d) because carbon dioxide is necessary to observe the results
c) because oxygen will disrupt the ability to observe the results
why are coliforms used as the indicator species when testing water for fecal contamination? a) because they are easy to see microscopically b) because they grow easily in water c) because they are found in feces and aer easy to detect d) because they will change shape when feces are present
c) because they are found in feces and are easy to detect
trypanosoma cruzi causes the condition called _______________ a) african sleeping sickness b) malaria c) chagas' disease d) babesiosis
c) chagas' disease
the kirby-bauer test is used for: a) determining the dose of antibiotic to use for an infection b) testing for pathogenic bacteria c) determining the susceptibility of a microbe to an antimicrobial agent d) testin the effectiveness of disinfectatns
c) determining the susceptibility of a microbe to an antimicrobial agent
a fungus is described as a mold when it grows ________ a) like a mushroom b) like bacterial colonies c) in filamentous strands d) as a human pathogen
c) in filamentous strands
TSY + streptomycin plate sectors were b) susceptible cells c) resistant cells d) susceptible cells + DNA e) susceptible cells + DNase + DNA which sector(s) did we expect growth
c) resistant cells -- because these cells were originally resistant to streptomycin and were not changed d) susceptible cells + DNA -- because the DNA was resistant to streptomycin, therefore this indicates the transformation of resistant DNA into susceptible cells occurred properly
an organism that decomposes dead organiv matter is called a(n) ________ a) autotroph b) parasite c) saprophyte d) pathogen
c) saprophyte
biochemical tests employing mannitol salt agar and eosiin methylene blue agar fall under the category of: a) respiration tests b) fermentation tests c) selective/differential media tests d) nutrient utilization tests
c) selective/differential media tests
which enzyme are you testing for when you put your organism on a glass slide and add hydrogen peroxide on top of it
catalaseq
in the colilert test used for checking the quality of milk samples, a yellow color production in the tube after incubation indicates the presence of ______ group of bacteria
coliform
the chromophore portion of a chromogen is responsible for _____ and the auxochrome portion is responsible for ______
color charge (dye)
what does the condenser do in a microscope
concentrates light to make the illumination uniform
in a microscope, what part concentrates light to make the illumination uniform
condenser
in addition to magnification and resolution, another feature (provided by staining) that is required to make a specimen visible is ________
contrast
a culture is added to a BBL dryslide using a wooden tootpick and it appears purple or blue within 20 seconds; which enzyme are you testing for
cytochrome c oxidase
which sector do you hope to have transformation occur
d - susceptible cells + DNA (resistant)
___________ is a combination differential media test we used in determining our unknowns: a) phenol red broth b) urea broth c) citrate slants d) SIM medium
d) SIM medium
the purpose of adding oil to a slide when viewing the specimen with the oil immersion objective is to: a) increase the magnification b) increase the resoltuion c) decrease the numerical aperture of the obj lens d) increase the limit of resolution (resolving power)
d) increase the limit of resolution
in order for water to be considered safe to drink, it must contain a) no coliforms b) no gram (-) bacteria c) less than 20 coliforms per 100 mL d) less than 1 coliform per 100 mL
d) less than 1 coliform per 100 mL
the organism that carries out its sexual phase in mosquitoes and an asexual phase in humans, resulting in lysis of erythrocytes, is __________ a) trypanosoma b) toxoplasma c) giardia d) plasmodium
d) plasmodium
what is the most critical step in gram staining
decolorizing
name the form of nitrate reduction that results in N2 gas production
denitrification (full reduction of nitrate to N2)
flat, raised, convex, pulvinate (very convex), and umbonate (raised in the center), are all descriptions of which colony morphology characteristic
elevation
in describing colony morphology, what are the types of margin
entire (smooth, with no irregularities) undulate (wavy) lobate (lobed) filamentous (unbranched strands) rhizoid (branched like roots)
an organism inoculated in an FTB tube that grows at the top and at the bottom/throughout the rest of the tube would be what kind of organism based on oxygen requirements
facultative anaerobe
if it takes a milk sample a long time to change color, that means there are (few/lots) of microorganisms present, meaning it is (poor/high) quality
few microbes high quality
in describing colony morphology, what are the types of elevation
flat raised convex pulvinate (very convex) umbonate (raised in the center)
after gram staining B. cereus, it appeared as purple colored rods, meaning it is gram ____
gram (+)
after gram staining P. aeruginosa, it appeared as pink colored rods, meaning it is gram ____
gram (-)
what are two characteristics of coliforms
gram (-) rods lactose fermentors
if an organism is capable of growing on simmons citrate agar medium, it will also change the color of the indicator present, from ______ to _____
green to blue
you inoculated a gram (+) organism onto an EMB plate and incubated at 37℃ overnight, what do you expect to see on the plate the next day
growth on streak but not growing outwards growth would be the same color as the agar
in an agar deep tube, what kind of growth would occur for a obligate anearobe
growth only at bottom of slant where oxygen content is low
in an agar deep tube, what kind of growth would occur for a obligate aerobe
growth only at the top of slant where oxygen ocntent is high
in mannitol salt agar, the selective component is __________
high salt concentration (7.5% NaCl)
what can possibly happen that may be bad if you pour the media onto plates before tempering it in a water bath to about 50℃
if you pour the media into a plate when it's too hot, it will condensate on the plate and contaminate the colonies in the media
how would the result (color) of staining a normally gram (-) organism change if the most critical step of gram staining was done incorrectly
it would appear purple because the crystal violet-iodine complex would not have been washed out properly, therefore the safranin dye would not ahve been able to be retained
in terms of dress, what are the two items required to be worn at all times in the lab
lab coat and closed toed shoes
the thick confluent growth of bacterial cells on a plate prepared for antibiotic sensitivity testing is called a(n) _______
lawn
if it takes a milk sample a short time to change color, that means there are (few/lots) of microorganisms present
lots of microbes poor quality
the longer it takes for color change of a milk sample in the methylene blue reductase test indicates the the number of microorganisms present is (higher/lower)
lower
in mannitol salt agar, the differential components are _________ and ________
mannitol phenol red indicator
entire (smooth, with no irregularities), undulate (wavy), lobate (lobed), filamentous (unbranched strands), and rhizoid (branched like roots), are all descriptions of which colony morphology characteristic
margin
in eosin methylene blue (EMB) agar, the selective components are ________ and ________
methylene blue dye eosin dye
it two or more species are present in a culture, it is called a _______ culture
mixed
in an MR-VP test , the methyl red indicator is added to test for organisms cpable of producing/doing ________ fermentation and the VP reagents are added to test for organisms capable of producing _______ as an end product
mixed acid fermentation acetoin and 2,3-butanediol as end products
in describing colony morphology, what are the types of texture
moist mucoid (sticky) butyrous (buttery) dry
in the nitrate reduction test, color change to red after addition of zinc dust indicates a (positive/negative) result
negative
the formation of a string in 3% KOH indicates that the isolate is a gram ______ organism
negative
you perform a water filtration experiment and calculate 2 coliforms per 100 mL of water. is this water sample suitable for human consumption?
no because it is higher than 1 coliform per 100 mL water. anything less than this standard would be considered safe
if the limit of resolution is higher than the actual distance of two points, would the two points be distinguished as two separate points
no, they would be blurred together as one
in a microscope, the ability of a lens to capture light is called what
numerical aperture
another name for a liquid medium (not having agar as a solidifying agent) is _____________
nutrient broth
in a microscope, what part produces the magnified real image
objective lens
when looking at a microscope, where can you see the numerical aperture value of the objective lens
objective lens value is ___x objective lens numerical aperture value is a decimal displayed as objective lens value/NAobjective (i.e. 60x/1.4 would mean 60x objective lens with a numerical aperture of 1.4)
an organism inoculated in an FTB tube that grows only at the top and not at the bottom/throughout the rest of the tube would be what kind of organism based on oxygen requirements
obligate aerobe
an organism inoculated in an FTB tube that does not grow at the top but only grows at the bottom/throughout the rest of the tube would be what kind of organism based on oxygen requirements
obligate anaerobe
in a microscope, this part produces virtual final image
ocular lens
in describing colony morphology, what are the types of optical properties
opaque translucent
opaque and translucent are descriptions of which colony morphology characteristic
optical properties
what does BSL 2 mean regarding the organisms that may be encountered in the lab
organisms are moderately infectious to the environment and people, but likely have treatments/vaccinations for them
which cellular structure, fundamentally different in gram positive and gram negative bacteria, is the primary reason that these two groups of bacteria stain differently during the gram stain procedure
peptidoglycan cell wall
in the nitrate reduction test, color change to red after addition of nitrate reagents A and B indicate a (positive/negative) result
positibe
inthe nitrate reduction test, no changein color after addition of zinc dust indicates a (postive/negative) result
positive
what does the objective lens do in a microscope
produce the magnified real image
what does the ocular lens do in a microscope
produces virtual final image
a culture which contains only one type/species of bacterium is called a _____ culture
pure
a culture which contains only one type/species of bacterium is claled a _______ culture
pure
you inoculated a gram (-) organism that is capable of fermenting lactose vigorously onto an EMB plate and incubated at 37℃ overnight, what do you expect to see on the plate the next day
purple/black colonies with metallic sheen
how can you check whether or not transformation actually occurred (i.e. what is the next step)
put cells on TSY and Str plate
fluid thioglycollate medium contains yest extract, casein, dextrose, sodium thioglycollate, L-cystine, resazurin, and a small amount of agar: ________ acts as an indicator and is colored ______ when oxidized
resazurin pink/red
in a microscope, what is the clarity of an image known as
resolution
in describing colony morphology, what are the types of shape
round (circular) irregular punctiform (tiny, pinpoint)
endo agar is both selective and differential. it selects for __________ bacteria and differentiates those that grow by their ability to __________
selects for gram (-) ability to ferment lactose
round (circular), irregular, and punctiform (tiny, pinpoint) are all descriptions of which colony morphology characteristic
shape
list the basic/broad categories used to describe colony morphology
size shape margin surface texture elevation color optical properties
in describing colony morphology, what are the types of surface
smooth rough wrinkled (rugose) shiny dull
fluid thioglycollate medium contains yest extract, casein, dextrose, sodium thioglycollate, L-cystine, resazurin, and a small amount of agar: what are the component(s) that function to reduce oxygen
sodium thioglycollate
smooth, rough, wrinkled (rugose), shiny, and dull, are all descriptions of which colony morphology characteristic
surface
moist, mucoid (sticky), butyrous (buttery), and dry, are all descriptions of which colony morphology characteristic
texture
what is the numerical aperture of a microscope
the ability of a lens to capture light
in a T streak, which area should have the most bacteria present
the area that was streaked first
in a T streak, which area should have the least bacteria present
the area that was streaked last
what is the resolution of a microscope
the clarity of an image
if an obligate aerobe grows at the top of the tube and throughout the rest of the tube, what likely occurred to cause this error
the tube is likely old and oxygen probably seeped through the entire tube
if the limit of resolution is 100 nm, will you be able to distinguish 2 points that are 200 nm apart as being separate or will they blur into one
they would be distinguished as two points because the actual distance apart (200 nm) > limit of resolution (100 nm)
in an agar deep tube, what kind of growth would occur for a facultative anaerobe
throughout entire tube along the slant
in the transformation lab, why does the DNase have to be added before the DNA in sector e
to ensure transformation is occurrign specifically because of DNase. if DNase was not added before DNA, the DNA + susceptible cells would start interacting/transforming, and we would not know what caused the transformaiton
what is the purpose of the small, inverted durham tube in the phenol red broth tubes
to test for gas production
what is the equation for total magnification
total magnification = (magnification of objective lens)(magnification of ocular lens)
(T/F): a clear area surrounding a disk saturated with an antimicrobial chemical after incubation shows that the inoculated bacteria have all been killed
true
organims that possess the enzyme _____ are able to break down urea into ammonia and CO2
urease
if you do use oil with your microscope, how do you clean it up before leaving
use lens paper to gently wipe off lens without applying pressure to it, then put lens cleaner on the lens paper and wipe off lens
what is a positive reaction (the actual observation) in the KOH test
viscous string formed
fungi are informally divided into two main groups: the unicellular _______ and the multicellular filamentous ________
yeasts molds
should you use immersion oil with the obj lens above 60x
yes
if the limit of resolution is lower than the actual distance of two points, would the two points be distinguished as two separate points
yes, they would be two separate points
what is the name of the clear area that surrounds antibiotic discs in the kirby-bauer test for antibiotic resistance
zone of inhibition
why is it important to heat fix cells before basic staining
-kills the bacteria -makes bacteria adhere to the slide -coagulates cytoplasmic proteins to make them more visible
what is the penalty for the first violation of the safety policy
0% quiz grade
order the following four reagents for gram staining using numbers 1-4: ethanol, safranin, iodine, crystal violet
1- crystal violet 2- iodine 3- ethanol 4- safranin
describe the procedure for entry into lab before starting work
1- have phone and water bottle put away in backpack or outside of the lab 2- put backpack away 3- put lab coat on 4- wash hands 5- wipe bench off with disinfectant
you are using a microscope with 60x objective with a 15x ocular lens and its condenser's numerical aperture is 1.1. you are using fluorescent light at a wavelength of 250 nm. The objective lens has a numerical aperture of 1.4. what is the limit of resolution of this microscope using the above lenses?
100 nm math: D = (250nm) / (1.1 + 1.4) D = 250nm/2.5 D = 100nm
use immersion oil for obj lens above ___x magnification
60x
you are using a microscope with 60x objective with a 15x ocular lens and its condenser's numerical aperture is 1.1. you are using fluorescent light at a wavelength of 250 nm. what is the total magnification of this microscope using the above lens?
900x math: (60x)(15x) = 900x
what is the biosafety level of the micro lab
BSL 2
what is the equation for calculating the limit of resolution of a microscope
D = (lambda) / (NAcondenser + NAobjective)
what do the letters stand for in the equation for limit of resolution
D = limit of resolution lambda = wavelength of light being used to image NAcondenser = numerical aperture of condenser lens NAobjective = numerical aperture of objective lens
(T/F): food or drink can be consumed n the lab when not working with organisms or hazardous materials
FALSE: food/drink can never be consumed in the lab
