The practice of cells turning on the production of some enzymes and turning off others in response to a changing environment is called

Adaption

Explanation:

In the case when the practice of cells turn on some enzymes production and turn off the others so that the response to the environment i.e. changed is known as an adaption.

In this,  the organisms are adjusted according to the environment

So as per the given statement, the adaption is the answer and the same is to be considered

I think the answer is Hypertonic

Explanation:

Hypertonic means having a higher osmotic pressure than a particular fluid, typically a body fluid or intracellular fluid. When the salt is added to the salt its is likely to cause a Hypertonic.