The effects of gibberellin and several other plant hormones are well-documented, but the exact mechanism of their action on enzymes and other proteins is still to be fully explained. Patterns of Growth and Development Seed Germination Germination is the resumption of growth after a time of arrested embryonic development. Environmental factors influence germination.
Oxygen moves in and allows the embryo to switch to aerobic metabolism.
Increased temperatures and number of daylight hours are also influential. Repeated cell divisions produce a seedling with a primary root. Primary Growth Patterns Cell division increases the capacity for growth, but only about half of the daughter cells will actually undergo enlargement. Water uptake drives cell enlargement. Early cell divisions may result in unequal distribution of cytoplasm.