Question

In the absence of substance M, a hypothetical LM operon is turned off. If substance M is abundant, it can bind to the repressor, which permits the polymerase to begin transcribing the DNA. In this case, LM is a(n) _______ operon and M acts as a(n) _______.

Answer 1

Answer:Inducible;inducer

Step-by-step explanation:

Induction is the phenomenon of increased synthesis of protein or and enzyme in response to certain signal. Such enzymes are called inducible and the signals are called inducer. Induction is turning ''on''the switch of a gene.

When M is present in the medium, M binds the repressor protein. The repressor-M complex is inactive which does not bind to the operator region of LM. Now RNAP can transcribe the structural genes of LM.

M switches the gene ''on''. Hence M is an inducer of LM. LM is an inducible operon