Is chlamydomonas a prokaryote or eukaryote

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 of the following is the earliest era of earth's geologic time scale? cenozoic mesozoic precambrian paleozoic

This is the interaction of two organisms where one is and the other is neither nor harmed.