What do you think is the reason that scientists divide the earth into two different sets of layers

What came first egg or chicken? and is tomato a vegetable or a fruit?

Actinobacteria sp. are fermenting organisms (which do you use oxygen to breathe) referred to as chemoorganohetereotrophs this means they break down organic material and convert it to inorganic material. which part of the carbon cycle does this describe

Which type of respiration takes place when there is no oxygen present? a. anaerobic b. mitochondrial c. cellular d. aerobica. anaerobic