There are three and they are the Atmosphere, lithosphere, and hydrosphere
Eukaryotes
Nuclear
Divide
Organelles
Membrane
Evolved
Molecules
Brane
Regulating
Active
Nucleus
Endoplasmic
Hope thats what you need!
Answer:
1.) stromatolites
2.) photosynthesis
3.) Ordovician
4.) Cambrian
5.) oxygen
6.) As Earth cooled, carbon dioxide dissolved in the early ocean. Cyanobacteria consumed carbon dioxide and converted it to oxygen. Methane was removed from the atmosphere as oxygen was produced, eventually leading to the Cambrian Explosion.
7.) Metabolic processes that use oxygen produce more energy than anaerobic metabolism. Simple diffusion of oxygen would limit the size of a multicellular eukaryote, but animals evolved ways to transport oxygen to their tissues, which permitted an increase in size.
Explanation:
From Penn
