UAMS Microbiology Exam #1 Questions With Correct
Answers
In |the |health |care |system, |the |physician |consults |with |the |patient |and |retrieves |a |specimen. |
The |specimen |is |then |sent |to |the |lab, |a |report |is |generated, |and |the |report |is |sent |to |the |
physician. |What |are |the |4 |things |included |in |the |report |from |the |micro |lab? |- |CORRECT |
ANSWER✔✔-Gram |stain, |culture, |organism |identification, |and |antimicrobial |susceptibility.
What |is |a |culturette |used |for? |- |CORRECT |ANSWER✔✔-Specimen |collection. |It |is |a |tube |closed
|on |the |bottom |and |open |at |the |top |with |swabs |inserted |into |the |culturette |container.
What |is |the |complete |procedure |done |by |the |lab |for |collecting |and |then |identifying |an |
organism? |- |CORRECT |ANSWER✔✔-Collect |the |specimen |with |a |culturette |tube, |plate |it |using |
either |an |agar |or |broth |medium, |incubate |the |culture, |and |then |ID. |Determine |antimicrobial |
susceptibility |and |report |results.
What |are |the |different |morphologies |of |bacteria? |- |CORRECT |ANSWER✔✔-Coccus, |
coccobacillus, |vibrio, |bacillus, |spirillum, |and |spirochete.
What |are |the |different |bacterial |arrangements |for |cocci? |- |CORRECT |ANSWER✔✔-Coccus |(one
|single |colony), |diplococci |(two |colonies), |staphylococci |(multiple |colonies |in |a |triangle |shape), |
streptococci |(multiple |colonies |in |a |linear |row), |sarcina |(multiple |colonies |that |can |be |on |top |
of |one |another |in |a |square |shape), |and |tetrad |(four |colonies |in |a |square).
What |does |bacillus |or |bacilli |refer |to? |What |about |Bacillus? |What |are |the |bacilli |
arrangements? |- |CORRECT |ANSWER✔✔-Rod |shaped. |The |genus |(Bacillus |anthracis). |Single |
bacillus, |diplobacilli, |streptobacilli, |and |palisade |(rods |laid |side |by |side, |forming |a |fence-like |
appearance; |can |also |be |V-shaped).
,What |does |the |term |pleomorphic |refer |to? |Ex. |Pleomorphic |bacilli |- |CORRECT |ANSWER✔✔-
Bacteria |that |is |capable |of |altering |its |morphology |to |take |on |many |different |shapes.
What |are |spores |and |what |do |they |allow |a |bacterium, |such |as |bacilli |with |spores? |- |CORRECT |
ANSWER✔✔-Spores |are |cells |with |very |thick |walls |that |can |survive |many |extremes, |allowing |a
|bacterium |protection |in |order |to |preserve |its |genetic |material.
What |are |the |two |different |forms |of |bacilli |rods? |- |CORRECT |ANSWER✔✔-Filamentous |and |
fusiform.
Who |invented |the |Gram |stain |and |staining |method? |What |are |the |reagents |involved? |How |is |
Gram |stain |able |to |work? |What |makes |some |bacteria |gram |pos |and |others |neg? |- |CORRECT |
ANSWER✔✔-Hans |Christian |Gram. |Crystal |violet, |iodine, |decolorizer, |and |safranin. |The |cell |
wall |structure |of |the |bacteria |is |what |determines |if |it |is |gram |pos |or |neg. |The |thick |
peptidoglycan |layer |on |gram |pos |MOs |retains |the |crystal |violet-iodine |complex. |On |gram |neg |
MOs, |there |is |only |a |thin |layer |of |peptidoglycan |under |a |layer |of |lipids. |The |lipid |layer |retains |
the |stain |and |the |decolorizer |then |dissolves |the |lipid |layer, |removing |the |crystal |violet-iodine |
complex.
What |is |the |counter |stain |that |is |used |alongside |Gram |stain |to |identify |the |Gram |neg |bacteria?
|How |does |this |work? |- |CORRECT |ANSWER✔✔-Safranin. |Once |the |decolorizer |dissolves |the |
lipid |layer |holding |the |crystal |violet-iodine |complex, |the |safranin |is |able |to |stain |the |thin |
peptidoglycan |layer |underneath, |causing |the |bacteria |to |appear |pink. |The |pink |bacteria |can |
then |be |identified |as |Gram |neg.
What |is |smear? |What |is |important |when |preparing |a |smear? |How |are |smears |heat |fixed |and |
why? |- |CORRECT |ANSWER✔✔-Cells |from |a |culture |are |taken |and |spread |over |a |thin |area |of |a |
slide |and |then |heat |fixed. |The |smear |doesn't |need |to |be |too |thin |or |too |thick, |otherwise |it |will
|be |unable |to |be |read |properly. |Smears |are |heat |fixed |using |a |bunsen |burner, |an |electric |
incinerator, |or |methanol. |This |is |done |to |kill |the |bacteria |on |the |slide, |prevent |bacteria |from |
washing |off |the |slide, |and |allowing |the |smear |to |take |up |stain |better.
, What |is |the |Gram |staining |procedure? |- |CORRECT |ANSWER✔✔-Place |the |slide |on |a |staining |
rack |and |cover |the |smear |with |crystal |violet |solution. |Let |stand |for |30-60 |seconds. |Rinse |with |
tap |water |to |remove |the |crystal |violet, |then |shake |off |excess |water. |Cover |the |smear |with |
Gram's |iodine |and |let |stand |for |30-60 |seconds. |Rinse |with |water, |then |shale |off |excess. |
Decolorize |the |smear |with |acetone-alcohol |and |rinse |with |water |as |soon |as |the |purple/blue |
color |no |longer |runs |off |the |slide. |*Be |careful |to |not |over |or |under |decolorize* |Shake |off |
excess |water |and |counterstain |with |safranin |for |30 |seconds, |rinse |with |water, |and |dry |slide |by |
air |or |by |blotting.
What |will |happen |is |the |decolorizer |is |left |on |too |long? |What |about |under-decolorized? |- |
CORRECT |ANSWER✔✔-Gram |neg |cells |such |as |human |cells |will |appear |washed |out |and |gram |
pos |bacteria |will |appear |gram |neg |or |partially |stained. |Gram |neg |cells |such |as |human |cells |will
|appear |dark |red |/ |purple |and |other |gram |neg |bacteria |appear |gram |pos.
How |will |damaged |cells |pose |as |a |source |of |error |when |staining? |How |does |overheating |a |
slide |pose |as |a |source |of |error? |What |about |improper |reagent |use? |What |about |excessive |
rinsing |and |prolonged |counterstaining? |- |CORRECT |ANSWER✔✔-Damaged |cells |are |a |potential
|problem |when |looking |at |older |culture, |they |will |not |take |up |stain. |This |can |be |due |to |
antibiotics. |Overheating |a |slide |distorts |cells |from |their |normal |shape, |causing |them |to |look |
weird |when |viewing. |Improper |reagent |use |can |be |a |source |of |error |when |one |is |omitted |or |
they |are |used |in |the |wrong |order. |Excessive |rinsing |can |wash |out |the |crystal |violet |or |crystal |
violent |iodine |complex |away, |Prolonged |counterstaining |might |cause |the |crystal |violet |complex
|to |be |leached |from |the |Gram |pos |MOs.
Why |is |media |used |in |microbiology? |What |are |the |different |broth |and |agar |medias? |What |is |
the |main |component |of |agar |and |at |what |temp |does |it |melt |and |remain |liquid |to? |How |are |
different |agars |created? |- |CORRECT |ANSWER✔✔-Media |is |used |to |culture |specimens, |isolate |
bacteria, |biochemicals |used |for |identification, |and |used |for |antibiotic |susceptibility.
Liquid |broth, |semi-solid |agar |(0.3-0.5%), |agar |slants, |and |solid |agar |(1-2%). |Polysaccharide |is |
the |main |component, |melting |at |100 |C |and |staying |liquid |until |45-50 |C. |Different |agars |are |
created |by |using |different |amounts |of |polysaccharide. |Semi-solid |has |less, |whereas |solid |has |
more.
Answers
In |the |health |care |system, |the |physician |consults |with |the |patient |and |retrieves |a |specimen. |
The |specimen |is |then |sent |to |the |lab, |a |report |is |generated, |and |the |report |is |sent |to |the |
physician. |What |are |the |4 |things |included |in |the |report |from |the |micro |lab? |- |CORRECT |
ANSWER✔✔-Gram |stain, |culture, |organism |identification, |and |antimicrobial |susceptibility.
What |is |a |culturette |used |for? |- |CORRECT |ANSWER✔✔-Specimen |collection. |It |is |a |tube |closed
|on |the |bottom |and |open |at |the |top |with |swabs |inserted |into |the |culturette |container.
What |is |the |complete |procedure |done |by |the |lab |for |collecting |and |then |identifying |an |
organism? |- |CORRECT |ANSWER✔✔-Collect |the |specimen |with |a |culturette |tube, |plate |it |using |
either |an |agar |or |broth |medium, |incubate |the |culture, |and |then |ID. |Determine |antimicrobial |
susceptibility |and |report |results.
What |are |the |different |morphologies |of |bacteria? |- |CORRECT |ANSWER✔✔-Coccus, |
coccobacillus, |vibrio, |bacillus, |spirillum, |and |spirochete.
What |are |the |different |bacterial |arrangements |for |cocci? |- |CORRECT |ANSWER✔✔-Coccus |(one
|single |colony), |diplococci |(two |colonies), |staphylococci |(multiple |colonies |in |a |triangle |shape), |
streptococci |(multiple |colonies |in |a |linear |row), |sarcina |(multiple |colonies |that |can |be |on |top |
of |one |another |in |a |square |shape), |and |tetrad |(four |colonies |in |a |square).
What |does |bacillus |or |bacilli |refer |to? |What |about |Bacillus? |What |are |the |bacilli |
arrangements? |- |CORRECT |ANSWER✔✔-Rod |shaped. |The |genus |(Bacillus |anthracis). |Single |
bacillus, |diplobacilli, |streptobacilli, |and |palisade |(rods |laid |side |by |side, |forming |a |fence-like |
appearance; |can |also |be |V-shaped).
,What |does |the |term |pleomorphic |refer |to? |Ex. |Pleomorphic |bacilli |- |CORRECT |ANSWER✔✔-
Bacteria |that |is |capable |of |altering |its |morphology |to |take |on |many |different |shapes.
What |are |spores |and |what |do |they |allow |a |bacterium, |such |as |bacilli |with |spores? |- |CORRECT |
ANSWER✔✔-Spores |are |cells |with |very |thick |walls |that |can |survive |many |extremes, |allowing |a
|bacterium |protection |in |order |to |preserve |its |genetic |material.
What |are |the |two |different |forms |of |bacilli |rods? |- |CORRECT |ANSWER✔✔-Filamentous |and |
fusiform.
Who |invented |the |Gram |stain |and |staining |method? |What |are |the |reagents |involved? |How |is |
Gram |stain |able |to |work? |What |makes |some |bacteria |gram |pos |and |others |neg? |- |CORRECT |
ANSWER✔✔-Hans |Christian |Gram. |Crystal |violet, |iodine, |decolorizer, |and |safranin. |The |cell |
wall |structure |of |the |bacteria |is |what |determines |if |it |is |gram |pos |or |neg. |The |thick |
peptidoglycan |layer |on |gram |pos |MOs |retains |the |crystal |violet-iodine |complex. |On |gram |neg |
MOs, |there |is |only |a |thin |layer |of |peptidoglycan |under |a |layer |of |lipids. |The |lipid |layer |retains |
the |stain |and |the |decolorizer |then |dissolves |the |lipid |layer, |removing |the |crystal |violet-iodine |
complex.
What |is |the |counter |stain |that |is |used |alongside |Gram |stain |to |identify |the |Gram |neg |bacteria?
|How |does |this |work? |- |CORRECT |ANSWER✔✔-Safranin. |Once |the |decolorizer |dissolves |the |
lipid |layer |holding |the |crystal |violet-iodine |complex, |the |safranin |is |able |to |stain |the |thin |
peptidoglycan |layer |underneath, |causing |the |bacteria |to |appear |pink. |The |pink |bacteria |can |
then |be |identified |as |Gram |neg.
What |is |smear? |What |is |important |when |preparing |a |smear? |How |are |smears |heat |fixed |and |
why? |- |CORRECT |ANSWER✔✔-Cells |from |a |culture |are |taken |and |spread |over |a |thin |area |of |a |
slide |and |then |heat |fixed. |The |smear |doesn't |need |to |be |too |thin |or |too |thick, |otherwise |it |will
|be |unable |to |be |read |properly. |Smears |are |heat |fixed |using |a |bunsen |burner, |an |electric |
incinerator, |or |methanol. |This |is |done |to |kill |the |bacteria |on |the |slide, |prevent |bacteria |from |
washing |off |the |slide, |and |allowing |the |smear |to |take |up |stain |better.
, What |is |the |Gram |staining |procedure? |- |CORRECT |ANSWER✔✔-Place |the |slide |on |a |staining |
rack |and |cover |the |smear |with |crystal |violet |solution. |Let |stand |for |30-60 |seconds. |Rinse |with |
tap |water |to |remove |the |crystal |violet, |then |shake |off |excess |water. |Cover |the |smear |with |
Gram's |iodine |and |let |stand |for |30-60 |seconds. |Rinse |with |water, |then |shale |off |excess. |
Decolorize |the |smear |with |acetone-alcohol |and |rinse |with |water |as |soon |as |the |purple/blue |
color |no |longer |runs |off |the |slide. |*Be |careful |to |not |over |or |under |decolorize* |Shake |off |
excess |water |and |counterstain |with |safranin |for |30 |seconds, |rinse |with |water, |and |dry |slide |by |
air |or |by |blotting.
What |will |happen |is |the |decolorizer |is |left |on |too |long? |What |about |under-decolorized? |- |
CORRECT |ANSWER✔✔-Gram |neg |cells |such |as |human |cells |will |appear |washed |out |and |gram |
pos |bacteria |will |appear |gram |neg |or |partially |stained. |Gram |neg |cells |such |as |human |cells |will
|appear |dark |red |/ |purple |and |other |gram |neg |bacteria |appear |gram |pos.
How |will |damaged |cells |pose |as |a |source |of |error |when |staining? |How |does |overheating |a |
slide |pose |as |a |source |of |error? |What |about |improper |reagent |use? |What |about |excessive |
rinsing |and |prolonged |counterstaining? |- |CORRECT |ANSWER✔✔-Damaged |cells |are |a |potential
|problem |when |looking |at |older |culture, |they |will |not |take |up |stain. |This |can |be |due |to |
antibiotics. |Overheating |a |slide |distorts |cells |from |their |normal |shape, |causing |them |to |look |
weird |when |viewing. |Improper |reagent |use |can |be |a |source |of |error |when |one |is |omitted |or |
they |are |used |in |the |wrong |order. |Excessive |rinsing |can |wash |out |the |crystal |violet |or |crystal |
violent |iodine |complex |away, |Prolonged |counterstaining |might |cause |the |crystal |violet |complex
|to |be |leached |from |the |Gram |pos |MOs.
Why |is |media |used |in |microbiology? |What |are |the |different |broth |and |agar |medias? |What |is |
the |main |component |of |agar |and |at |what |temp |does |it |melt |and |remain |liquid |to? |How |are |
different |agars |created? |- |CORRECT |ANSWER✔✔-Media |is |used |to |culture |specimens, |isolate |
bacteria, |biochemicals |used |for |identification, |and |used |for |antibiotic |susceptibility.
Liquid |broth, |semi-solid |agar |(0.3-0.5%), |agar |slants, |and |solid |agar |(1-2%). |Polysaccharide |is |
the |main |component, |melting |at |100 |C |and |staying |liquid |until |45-50 |C. |Different |agars |are |
created |by |using |different |amounts |of |polysaccharide. |Semi-solid |has |less, |whereas |solid |has |
more.
