A strain of E.coli has the genotype (and phenotype)leu^- lac^-.This notation means that this strain if bacteria is unable to: A)metabolize the amino acid leucine and synthesize the sugar lactose. B)utilize the amino acid leucine and synthesize the sugar lactose. C)utilize the amino acid leucine and the sugar lactose. D)synthesize the amino acid leucine and utilize the sugar lactose. E)synthesize the amino acid leucine and the sugar lactose.

Question

Quizplus · Accepted Answer

The notation "leu^-" and "lac^-" indicates that the E. coli strain cannot synthesize the amino acid leucine (leuS1) and cannot utilize the sugar lactose (lacU1), as indicated by the "S1" (synthesis) and "U1" (utilization) designations.

A Strain of E