Which has is made up most of earths eatly atmosphere

Does mitochondria still meet the definition of a eukaryote why or why not?

How does buring fossil fuels impact does carbon cycle? what large impact does this have on the envirnment?

Students in biology are studying the macromolecules of life. they used a calorimeter to determine the calories in various types of food. once the lab was completed, the students ate the left over food samples. monica commented that in just 6 or 7 "chews" of the saltine, it was gone; nothing but a sticky paste in her mouth. elaborate on what happened chemically while chewing the saltine. include the macromolecules present.