Marine protozoa dont have a contractile vacuole why?

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.

Which phase of the cell cycle ensures that identical copies of the dna are made for daughter cells?

Explain how the parts of the peripheral nervous system work with the central nervous system to produce a response to the stimulus