BIOL202 Week 6 Lab 6 Quantitation of Cultured Microorganisms APU
Eachquestiononthelabworksheetmustbeansweredcompletely,thoroughly,incompletesentencesand correctlyin orderto beconsideredforfullcredit Ifthequestionasksyoutodoresearchorfindasource,areputable,credibleand/orscholarlysourcecitationmustbeincluded inorder tobeconsidered for fullcredit Ifamathformulaisrequiredtoarrivetoananswer,workmustbeshownotherwise,nocreditwill beawarded Pre-Lab Questions 1. A serial dilution of a sample has an unknown concentration of microorganisms.A countable plate has 44 CFU. It was inoculated with 0.1 mL of a 10-1 dilution.Whatwasthepopulationdensityoftheoriginalsamplepermilliliter?(10points) 2. Compareandcontrasttheplatecountmethodsforbacterialandviralpopulations.(10points) 3. Manyofthequantitativemethodsdiscussedarepopularbecausetheyenablethemicrobiology researcher to selectively count live cells only. Why do you think this mightbe an important or desirable feature in a medical or environmental research situation?Provide a scenario in which it might not be important to differentiate between live anddeadcells when countingcellnumbers.(10points) Experiment 1 Results Tables Table1:Experiment1GrowthResults(10points) ***Enteronly thenumber ofcoloniescountedfrom eachplate intothe secondrow*** Experiment1Post-LabQuestions 1. What was the population density of the original sample? (use a countable plate tocalculatethis)(10 points) 2. Did all of the colonies on the countable plate(s) have a similar appearance? If not, howwouldyou explain this? (5 points) 3. Describe a different quantitative method to estimate the number of microorganisms forthis sample? What are the advantages and disadvantages for using this alternativemethodforthis sample? (10points) 4. What are some potential sources of error in the serial dilution/direct plate countingmethod?(10 points) 5. Per the USDA, whole, unpasteurized fresh eggs can contain no more than 50,000CFU/mLbacteriainastandardplatecount.Youarecuriousifthefresheggsthatyoubuy from your neighbor are considered safe to consume so you use your eScienceMicrobiologykittotesttheseeggsusingdirectplatecountafterserialdilution.Afteryoucompletetheexperiment,youobtain74countablecoloniesfromthe10-2dilutionplate.Theinoculumvolumeyouplated was0.1mL.(20points) a. Howmanybacteriaarepresentin1mLoftheeggyousampled? b. AretheseeggsconsideredsafetoconsumeperUSDAstandards?
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- Subido en
- 5 de enero de 2024
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- 2022/2023
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biol202 week 6 lab 6 quantitation of cultured micr
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biol202 week 6 lab 6 quantitation of cultured mic
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biol202 week 6 lab 6 quantitation of cultured m
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biol202 week 6 lab 6 quantitation of cultured