Question

BIS 101 Homework 04 Dr. Crowder nexperiment is performed in Escherichia coli using the parents Hfr arg str and Farg lys met his stor. The mating was interrupted at several d on several different media with the following results. The table below shows the number of colonies obtained on different media as es obtained on different media as indicated. a Minimal medium plus streptomycin plus Histidine Arginine Arginine Lysine Histidine Histidine Methionine Methionine Lysine ine Arginine Lysine Methionine Time (min.) 0 0 20 200 600 0 0 55 50 400 1000 0 40 75 550 1000 What is the order of the four auxotrophic genes with respect to the starting point of transfer (0)?

Answer 1

Answer His Arg Met Lys

Justification

Autotrophic mutant are unable to synthesize their own food. Hence, they are dependent on external environment for survival.

Growth at 10min in medium containing Arg Lys Met Indicates transfer of histidine

Similarly,

20 His Lys Met Indicates transfer of Arginine

30 Arg His Lys indicates transfer of methionine

40 Arg His Met indicates transfer of lysine