Definitely decompose dead organisms, otherwise there would be no oil for us.
White blood cells ( lymphocytes is correct though)
Diffusion, facilitated diffusion, osmosis
Human evolution known to be a process in which species adapt to certain conditions of life, and in the battle of life and death, they are forced to become stronger in order to survive in the world. Diseases have always been present during the evolution, acting themselves as a natural selector-the weaker organisms get sick and die.
Two traits that represent a sustainable society is an emphasis on egalitarianism - where there would be a tendency to strive towards a society of equals. Another would be an emphasis on using renewable energy.
On the other hand, an unsustainable society would have an emphasis on using fossil fuels due to being cheaper and having an ever-increasing productions of goods, not considering how taxing this might be on the planet.