The ozone layer is located in which layer of the atmosphere? MCQ with Answer and Explanation

Explanation:
In the lac operon, the 'i' gene (regulatory gene) constitutively produces a repressor protein. In the absence of lactose (the inducer), this active repressor binds specifically to the operator region of the operon. The operator overlaps with the promoter, physically blocking RNA polymerase from binding to the promoter or moving forward to transcribe the structural genes (z, y, a). When lactose is present, it binds to the repressor, inactivating it and allowing transcription.

Explanation:
Acetylcholinesterase degrades acetylcholine into acetate and choline, terminating the synaptic signal. Choline acetyltransferase synthesizes ACh, MAO and COMT degrade monoamines.

Explanation:
The soft palate, including the uvula, elevates during swallowing to close off the nasopharynx, preventing food from entering the nasal passages. The epiglottis closes the larynx, the tongue pushes food.