The answer is Adrenaline
Adrenaline is a stress hormone secreted by the adrenal glands and some other neurons when a person is frightened, excited or generally in stress.
It prepares our body for it's 'fight or flight' mechanism and tightens muscles for exertion.
After a bank robbery, most people feel a rush of adrenaline.
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(4) organisms in a changing environment must adapt to acquire necessary traits and survive