Why are most autotrophs referred to as the producers of the biosphere?.

What substance acts to prevent sudden ph changes in bodily fluids?

The double bond between a carbon atom and two oxygen atoms (a molecule of carbon dioxide) has two characteristics. what are they? a. an ionic bond is formed between the oxygen and carbon atoms. b. four valence electrons are shared. c. two valence electrons are shared. d. valence electrons are shared between oxygen atoms.

What is the difference between a meteoroid and a meteor?