To perform photosynthesis, plants need three things: carbon dioxide, water, and sunlight.
        
                    
             
        
        
        
The correct answer to this is:
“Astrocytes”
Astrocytes also called star cells due to their shape are the
most abundant glial cells in the brain. Extensions from these cells encase
capillaries and offer extra control over which materials enter or leave the
intercellular fluid of the CNS thus acting like a permeability membrane.
 
        
             
        
        
        
Endorphins are brain chemicals
known as neurotransmitters which are released when the body feels a certain
amount of stress and pain. Endorphins alter the communication of pain in the
body by interacting with the opiate receptors and blocking the synapse so that signals
cannot be sent to the brain in order to reduce an individual perception of pain.