AP BIOLOGY

Detailed explanation-1: -In botany, secondary growth is the growth that results from cell division in the cambia or lateral meristems and that causes the stems and roots to thicken, while primary growth is growth that occurs as a result of cell division at the tips of stems and roots, causing them to elongate, and gives rise to primary tissue.

Detailed explanation-2: -The vascular cambium is responsible for the lateral (secondary) growth of plants, a process which must be carefully regulated in order to ensure holistic development of the plant vasculature. Figure 1. Schematic representation of vascular organization in the Arabidopsis inflorescence stem (A–C) and root (D–F).

Detailed explanation-3: -The Vascular Cambium and Secondary Growth. The vascular cambium and cork cambium are secondary meristems that are formed in stems and roots after the tissues of the primary plant body have differentiated. The vascular cambium is responsible for increasing the diameter of stems and roots and for forming woody tissue.

Detailed explanation-4: -With the onset of the secondary growth, fascicular cambia are interconnected with interfascicular cambia located between the vascular bundles, forming a complete vascular cambium in woody stems (Figure 1). The interfascicular cambia are known to originate from the parenchymatic cells in the interfascicular region.

Detailed explanation-5: -The vascular cambium in dicot stem is partly primary and partly secondary in origin. The intrafascicular cambium present inside the vascular bundle in the dicot stem is primary in origin while the interfascicular cambium formed from the cells of medullary rays is secondary in origin.