Variation means difference in genetic makeup between individuals within a specie.
Answer:
It is predominantly solid but in geological time it behaved as a viscous fluid.
Explanation:
Answer:
Areas where the myelin sheath has degenerated
Explanation:
Multiple sclerosis is a disease of the nervous system where the myelin sheath is damaged, and impairs its ability of conducing signals in the affected nerves, causing serious deficiencies in many life aspects (movements, sensations, cognition etc).
Answer:a/e/d I doubt case d
Explanation: