The Plate Count Method Was Used to Estimate the Number

question 60

Multiple Choice

The plate count method was used to estimate the number of bacteria in a culture over time.Serial dilutions were made of culture samples at various time points.A 0.1 ml portion of the 10⁻⁶ dilution was spread over the surface of a nutrient agar plate for each time point.The plates were incubated for 24 hrs and the colony forming units (CFU) were counted on each plate.A total of 45 colonies were counted on the plate for the 30 minute time point.What was the cell population for this time point?

• A)4.5 X 10⁴ CFU/ml
• B)4.5 X 10⁵ CFU/ml
• C)4.5 X 10⁶ CFU/ml
• D)4.5 X 10⁷ CFU/ml
• E)4.5 X 10⁸ CFU/ml

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Definitions:

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Petitions or demands made by formerly enslaved individuals following the Civil War, often regarding civil rights and land ownership.

Homestead

A dwelling with its land and buildings, occupied by the owner as their primary residence, often associated with historical laws granting land to families for farming or settlement.

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