Answer:
3 would be my best guess
Explanation:
we dont depend on it
its not harmful but that wouldn't be a reason to have it
it doesnt look cool
Answer:
a) Astrocytes
Explanation:
The astrocytes are components of the central nervous system that provide the necessary supports that the brain needs to perform vital tasks such as learning and other daily activities. They are typical cell types in the central nervous system that aid blood flow in the brain as well as the migration of neurons.
Answer:
they are not permanently altered by the reaction they catalyze