The plant as a whole organism, and ecological factors

Although green plants are diverse, they share much in common: all are built of cells, similar cells form tissues, and tissues form organs (root, stem, leaf, flower, fruit). A plant is a living organism: it feeds, breathes, grows, blooms and bears fruit, and reproduces. Organs are closely linked, and if one stops working the others suffer. Take cotton: its taproot system constantly absorbs water and mineral salts and passes them to the stem; the stem’s tubes carry them to the leaves; in the leaves organic matter is made by photosynthesis and spreads to all organs. After the budding stage cotton begins to flower from the bottom upward: bolls from the first flowers ripen earlier, and the plant keeps feeding the others. If the root supplies little water, leaves make little organic matter; if there are few leaves, roots, flowers and fruit do not grow. A plant cannot live without its environment: it needs soil, water, light, warmth and oxygen. That is why a mountain juniper does not grow beside saksovul in desert sand: each is adapted to its own conditions.