A Double Infection Experiment Is Conducted to Determine the Distance

question 30

Multiple Choice

A double infection experiment is conducted to determine the distance between two markers in the bacteriophage RB49,a phage similar to T2 and T4.A mutation in the first marker (F13^-) results in the inability to grow on E.coli strain B178,while a mutation in the second marker (P6^-) prevents the phage from growing at high temperature.A permissive E.coli strain is infected with both F13^- and P6^- phages,and the lysate is analyzed.1002 plaques were formed on a lawn of permissive E.coli at 37ºC,and out of these 1002,49 also formed plaques on E.coli B178 at high temperature.What is the predicted frequency of phages with genotype F13⁺P6^- in the lysate?

• A)5%
• B)45%
• C)47.5%
• D)90%
• E)95%

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