B -the absence of the inducer, but not in its presence
Explanation:
In positive repressible regulalor mechanisms transcription of the structural gene(s) occurs in the absence of the inducer because proteins are normally bound to the pertinent DNA segment. when an inhibitor is bound by the inducer, it is prevented from binding the DNA. which will the stops the activation and transcription of the structural genes.
Example of positive repressible regulator is Activator .
Regulating the rate of transcription is a mechanism of gene regulation leading to the productionn of more than one protein product from a single gene.
Platelets often referred to as thrombocytes, are membrane-bounded cell fragments that are obtained from the dissociation of bigger precursor cells referred to as megakaryocytes, that are produced from stem cells in the bone marrow.
Platelets are necessary for the blood clotting activities, making it very important for wound healing.
<span>If an orange powder coating the bottom of rivers from water runoff through old coal mines is called acid mine drainage. Acid mine drainage is an outflow of acid water that came from coal mine areas or some metal mine areas.</span>
