You plate colonies of E. coli with the lac operon genotype of I-P+O+Z+CAP+ on 1) a medium containing only glucose, and 2) a medium containing only lactose. You isolate mRNA from bacteria from each medium and do a Northern blot with a probe for β-galactosidase. Draw the results.

A complete collection of single-use and high-throughput electrocompetent and chemically competent E. coli

Choosing the ideal competent cells for your cloning applications and workflows is a critical component of success. Aspects to consider when selecting your competent E. coli strain include:

Transfection method – chemical versus electroporation

Transformation efficiency – bacterial strain and genotype

Downstream application – protein expression, library production, general cloning

answer: d. load

a river's load refers to the natural phenomena in which the sediments, rocks   stones, boulders and other deposits are removed and picked from the bottom bed of the river due to the abrasion resulted by the high speed water current.