What organelle regulates cell contents? A. Ribosome
B. Vacuole
C. Nucleus
D. Cell Membrane

HELP ME PLEASE

The trp operon in e.coli regulates genes that code for enzymes required for synthesis of the repressible operon. when tryptophan is not available amino acid tryptophan. the trp operon is a in the environment, the trp repressor protein activeinactiveregulated. therefore, rna polymerase can bind to the genes to begin transcription.

What class of levers is shown in this image?

In which energy level are valence electrons located?