The myelin sheath that covers many cns axons is formed by

a) astrocytes.
b) satellite cells.
c) oligodendrocytes.
d) microglia.
e) ependymal cells.

In the water cycle , when does water undergo a chemical change

According to theories of how life began, how did early organic molecules begin to separate from the outside world? a: specialized enzymes were required b: chains of amino acids created a barrier c: formation of microspheres or vesicles d: rna catalyzed the formation of membranes

Due tonight 10 points will mark brain