Woah! I am flabbergasted at the rate at which the bean plant is growing. It has amassed so much height and now has two full, true leaves a good distance above the cotyledon. These leaves are produced by axillary buds, and the terminal bud is visible between them. This is where auxin is produced, a hormone that induces growth via cell division, as well as inhibiting the growth of lateral buds lower on the stem.
The terminal bud also houses the shoot apical meristem, where undifferentiated cells undergo mitosis, increasing the shoot’s height. The apical meristem gives rise to three primary meristems, the protoderm, ground meristem, and procambium, which produce the epidermis, ground tissue, and vascular tissue, respectively.
Secondary growth, which increases the width of the stem, is induced by the lateral meristems: cork cambium and vascular cambium. The structures involved in secondary growth, including the vascular system, are diagramed below.
