Refer to the Figure, Showing Two Culture Plates

question 119

Multiple Choice

Refer to the figure, showing two culture plates. A researcher transfects bacteria with a gene that does not confer a selectable phenotype, so he also includes a gene for resistance to the antibiotic neomycin on a separate DNA strand.After the transfection, the researcher divides the culture into two equal fractions.Fraction 1 is spread onto a plate without neomycin (Plate A) , and fraction 2 is spread onto a plate with neomycin (Plate B) .Considering both plates, how many colonies in total are composed of bacteria that have been successfully transfected?

• A) 15
• B) 20
• C) 5
• D) 10
• E) The total cannot be determined.

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