instruction:
Given a scientific question, generate a correct answer to it.
question:
What is the outer layer of an axon that acts like a layer of insulation, similar to the plastic that encases an electrical cord?
answer:
myelin sheath

question:
What is another term for ghost sharks?
answer:
chimaera

question:
Soils with higher capacities generally have a larger reserve of what?
answer:
mineral nutrients