<span>Guarana i think but i'm not very sure</span>
        
             
        
        
        
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:
Algal blooms can reduce the ability of fish and other aquatic life to find food and can cause entire populations to leave an area or even die. ... Nutrient pollution fuels the growth of harmful algal blooms which have negative impacts on aquatic ecosystems.
Explanation:
 
        
             
        
        
        
Answer:
The same number of each type of atom will always be present before and after a chemical reaction takes place.
Explanation: