Answer:
By action potential nerve contract the muscle
Explanation:
The muscle contract when the nervous system sends action potential to the muscle. So the nervous system delivers signal to muscle, the first signal reaches the neuromuscular junction. The signals are passed by a chemical messenger called neurotransmitter release by motor neurons, the chemicals bring reaction and shorten the muscle fibre. When neurotransmitter are absent or reduce in concentration the process reverse and muscle relax again.
They drink water and then get rid of the waste
Answer:
Following are the four combinations of active or inactive regulatory proteins that could be present anytime in the cell:
Active repressor , Active activator.
Active repressor, Inactive activator.
Inactive repressor, Active activator.
Inactive repressor, Inactive activator.
Explanation:
Use the attached diagram for
explanations on the four combinations of active or inactive regulatory proteins in cells.
I'll give you the first one: it's a reactant of respiration. if you want the other answers just dm me so its easier to communicate
