Plants develop by creating a large number of immature cells, which are then expanded and matured. The tops and edges of the plant parts are where the new cells are created (roots, stems, leaves). These cells expand behind the regions where new cells are being produced. Water pressure must build up inside the expanding cells in order to force the cell walls to stretch (enlarge). Plant metabolites (sugars, proteins, etc.), which are integrated into the new plant material created by cell expansion, are necessary for cell enlargement. The sugars created by sunlight are used to create the metabolites. It takes light energy to power photosynthesis.
Therefore, for a plant to expand, it needs new cells, lots of water inside the plant, and active photosynthesis to make lots of metabolites, which causes the cells to grow bigger. The plant's hormones and enzymes work together to carry out the intricate system. Genes on the chromosomes of the cells carry out the creation of enzymes (proteins) and hormones. A magnificent, flawless, graceful process when the right environmental factors are present (light intensity, temperature, moisture, and nutrients). Self-programmed, self-executing, and totally independent of us. A redwood or a dandelion might result from the procedure. been doing it for a very long time.
thanks,
eddie