Autotrophs are organisms that can make their own food for the biosphere.
This term comes from the Greek terms:
Auto- meaning "self" and Troph- meaning "feeding or growth"
So autotroph quite literally means "to feed oneself". Autotrophs, for the most part, use photosynthesis from sunlight to produce their own sugars.
Plants are the primary autotrophs on Earth!
During aerobic respiration, complete oxidation of carbohydrates takes place. Glucose is broken down by oxygen to release energy, while carbon dioxide and water are the by-products of the reaction. The released energy is used to make a special energy molecule called Adenosine triphosphate (ATP).
The geologic principle that is the reason rock layers typically form parallel to each other is called ''Original Horizontality.''