What proof do you know have that living things are similar when viewed through a microscope?

Whether living or non living: When you put a sample of tissue under a microscope, if u can see a cell membrane, and can identify some cell structures like nucleus, mitochondria, vacuoles etc. , it was living, if not, its a non living thing.

Explanation:

Water is of major importance to all living things; in some organisms, up to 90% of their body weight comes from water. Up to 60% of the human adult body is water.different people have different percentages of their bodies made up of water. Babies have the most, being born at about 78%. By one year of age, that amount drops to about 65%. In adult men, about 60% of their bodies are water.