A Competent Bacterial Strain That Has the Genotype A^- B^-

Multiple Choice

A competent bacterial strain that has the genotype a^- b^- c⁺ is transduced with a P1 phage carrying a fragment of donor chromosome with the a⁺ b⁺ c^- alleles. The following number of transductants were found after screening for the selectable marker a⁺. $$\begin{array} { | c | c | } \hline \text { Transductant Genotyp } & \text { Number } \\\hline a + b - c + & 160 \\\hline a + b + c + & 360 \\\hline a + b + c - & 460 \\\hline a + b - c - & 20 \\\hline\end{array}$$ Which of the following conclusions is false?

A) The selected marker screen will inhibit growth of transductants with the genotype a^- b⁺ c^- .
B) The transduction frequency between a and b is 82%.
C) Gene a and gene b are closer together than gene a and gene c.
D) The gene order is acb.
E) The transduction frequency between a and c is 48%.