Besides gas exchange, one of the biggest problems of a terrestrial plant is related to the availability of water and its loss, because for photosynthesis it is essential to obtain, in addition to carbon dioxide, water.
The problem of water loss through leaves is partly minimized by the presence of lipid cuticles, on the exposed faces of the epidermis, which waterproof them. However, this makes gas exchange difficult.
The existence in the tracheophytes of adjustable epidermal openings (the stomata) that allow gas exchange and at the same time help to avoid excessive water vapor loss is an important adaptive mechanism.
Water and nutrient transport in a tracheophyte occurs in part by cell-to-cell diffusion, and most of the way occurs within conductive vessels.
Initially, the absorption of water and mineral nutrients occurs by the piliferous zone of the root. The different types of ions are obtained actively or passively and water is absorbed by osmosis.
A mineral aqueous solution is formed at raw sap or inorganic sap. This solution moves from cell to root cell until it reaches the xylem vases (or wood) in the center of the root. From there, the transport of this sap occurs entirely within the woody vessels to the leaves. Once there, nutrients and water diffuse into the cells and are used in the photosynthesis process.
Organic compounds made in the cells of the leaf chlorophyll parenchyma diffuse into another set of conductive tissue vessels called phloem or free. Within the Liberian vessels, this organic sap or elaborate sap is conducted until it reaches the stem cells of a fruit, bud, bud, etc. where it is used or stored.