They are like that because they can't always be faulty and may have at least some spark of truth to this theory also as stated earlier a theory in scientific terms is just an observation so it can't really be turned down hence theory.
Answer:
they are Na+, K+ and Ca2+ ion channels.
Explanation:
Ionotropic acetylcholine receptors are also called nicotinic acetylcholine receptors because beside acetylcholine (Ch) they respond to nicotine. These receptors are primary receptors in muscle for motor nerve-muscle communication that controls muscle contraction.
Two molecules of ACh are required for receptor to open. Since the receptors are linked to ion channels, the channels open. Opening of the channel allows positively charged ions to move across it: sodium enters the cell and potassium exits.
Answer:
Mutualistic means that both organisms benefit.
Explanation:
The acacia tree provides shelter and food to the ants, while the ants protect the tree from other animals.