Oligodendrocytes . a. regulate oxygen, carbon dioxide, nutrient and neurotransmitter levels around neurons in ganglia b. remove cell debris, wastes, and pathogens by phagocytosis c. maintain the blood-brain barrier and provide structural support d. line the ventricles of the brain and the central canal of the spinal cord e. provide structural framework and myelinate the central nervous system (CNS) axons

Hurry which of these is true about index fossils? a) are very scarcely found b) used as guides in relative dating c) found in the youngest layer of the rock d) used as reference points in absolute dating

What is one energy transformation that is taking place in the photo? radiant energy to thermal energy thermal energy to nuclear energy chemical energy to thermal energy radiant energy to chemical energy

The table below shows data for a population of fish in a pond. fish body color # of fins scales? tail shape a silver 4 yes fan b pink 4 yes flat c black 4 yes fan d orange 4 yes flat e orange 4 yes fan f silver 4 yes flat which of the above characteristics would be most in developing a classification system for the fish? a. body color and tail shape b. presence of scales and tail shape c. body color and number of fins d. number of fins and presence of scales