1. hydrosphere: the system that contains all forms of water; liquid, solid and gas
2. biosphere: the sphere that contains all living things
3. atmosphere: the system that contains the gaseous layer of a planet
4. cryosphere: the system that contain the frozen ice portion of a planet
5. lithosphere: the system that contains the solid rocky crustal portion
It makes their blood sugar stay leveled
Answer:
In biology, cell theory is the historic scientific theory, now universally accepted, that living organisms are made up of cells. Cells are the basic unit of structure in all organisms and also the basic unit of reproduction. ... Cell theory was eventually formulated in 1839.