The water content in living organisms is 60–75% of their mass, and in some, for example, jellyfish, up to 98%. In the leaves and succulent fruits of plants, the water content can also reach 98%.
The amount of water varies in different tissues and organs. So, in a person in the gray matter of the brain, its content is 85%, and in bone tissue – 22%. The highest water content in the body is observed in the embryonic period (95%) and gradually decreases with age.
The water content in various organs of plants varies widely. It varies depending on environmental conditions, age and type of plants. Thus, the water content in lettuce is 93–95%, and corn – 75–77%. The amount of water varies in different organs of plants: in the leaves of sunflower water contains 80-83%, in the stems – 87-89%, in the roots – 73-75%. A water content of 6–11% is characteristic mainly of air-dried seeds, in which vital processes are inhibited. Water is contained in living cells, in the dead elements of xylem and in intercellular spaces. In the intercellular spaces, water is in a vaporous state. The main evaporative organs of the plant are leaves. In this regard, it is natural that the greatest amount of water fills the intercellular spaces of the leaves. In the liquid state, water is in various parts of the cell: the cell membrane, vacuoles, and cytoplasm. Vacuoles are the most water-rich part of the cell, where its content reaches 98%. At the highest water content, the water content in the cytoplasm is 95%. The lowest water content is characteristic of cell membranes. Quantifying the water content in cell membranes is difficult; apparently, it ranges from 30 to 50%. The forms of water in different parts of the plant cell are also different.