Answer:
One type of control that occurs at the DNA level is the regulator genes. The regulator genes synthesize a repressor molecule that binds to the operator and stops transcription of the structural genes. Whenever there is enough amount of structural genes made, a repressor molecule will bind to the operator region and stop further transcription.
One type of control that occurs at the RNA level is RNA splicing. By this method, different proteins can be made by a single RNA transcript.
