E. coli cells were spread on an agar plate, producing 1000 colonies.  The colonies are replica plated on two agar plates containing the antibiotic kanamycin and one agar plate without antibiotics.  All of the colonies are able to grow on the agar plate without antibiotic but only 4 colonies are able to grow on each of the agar plates containing kanamycin.  You notice that the four colonies that grew on each of the kanamycin containing plates are in the exact same position.  This demonstrates

#Question id: 4684

#Unit 3. Fundamental Processes

The depicted region contains two genes (cI and cro) and three promoters (PR, PL, and PRM), these promoters are direct the transcription such as;

a) PR and PL are is a weak promoter and only directs efficient transcription when an activator is bound just upstream

b) PR and PL are strong, constitutive promoters, they bind RNA polymerase efficiently and direct transcription without     help from an activator

c) PRM, is a weak promoter and only directs efficient transcription when an activator is bound just upstream

d) PRM are strong, constitutive promoters, they bind RNA polymerase efficiently and direct transcription without help from an activator

Which of the following from the above combination is correct ?

#Question id: 4683

#Unit 3. Fundamental Processes

A very unstable protein in E. coli; it is degraded by a specific protease called FtsH (HflB), encoded by the hfl gene.

#Question id: 4682

#Unit 3. Fundamental Processes

what will happen, when repressor bound at OR1 and OR2,

#Question id: 4681

#Unit 3. Fundamental Processes

The promoters whose activities are controlled by products of the genes transcribed from PR and PL

#Question id: 4680

#Unit 3. Fundamental Processes

A protein is a transcriptional activator,  which binds to a site upstream of a promoter called PRE and stimulates transcription of the cI (repressor) gene. This activator protein is

#Question id: 4679

#Unit 3. Fundamental Processes

Activated RecA stimulates autocleavage of