Given a scientific question, generate a correct answer to it.

Example Input: Both fats and oils are made up of long chains of carbon atoms that are bonded together. what are these chains called?
Example Output: fatty acids

Example Input: The fossilized skeleton of archaeopteryx looks like that of a dinosaur, but it had what structures modified for flight, a trait associated only with birds among modern animals?
Example Output: feathers

Example Input: What nervous tissue cells play a supporting role to neurons?
Example Output:
glial cells