Answer:
1. The cell needs to produce energy (for example, energy in form of ATP)
2. The increase in the temperature is due to the activation of the metabolism
3. It is necessary that red blood cells may transport oxygen to the cells
4. It is necessary to activate the metabolism by physical exercise
5. It is necessary to adjust the osmotic pressure into the cell
6. It is necessary to adjust the osmotic pressure outside the cell
7. The cellular homeostasis is maintained by coordinating the entry and exit of molecules such as metabolites, nutrients, ionic liquids, etc.