How does secondary growth take place in dicot plant.
How does secondary growth take place in dicot plant.
Secondary growth is seen in dicots. Most monocots and herbaceous plants undergo little or no secondary growth.
Cambium is a thin layer of actively dividing cells which are responsible for secondary growth of plants. Cambial cells are undifferentiated cells which have the ability to get differentiated into different types of cells. Two types of cambium present in plants are vascular cambium and cork cambium.
Secondary growth:
Secondary growth is the increase in the girth of the stems and roots of plants. Secondary growth is brought about by lateral meristems, vascular and cork cambiums.
Secondary growth in dicot roots:
Secondary growth is also observed in roots to bring about increase in diameter of the roots.
*Pericycle cells opposite to xylem cells start to divide periclinally. Inner layer of cells gives rise to vascular cambium and outer layer of cells remain as the cells of pericycle.
* Vascular cambium forms a continuous layer around the primary xylem.
*Vascular cambial cells continue to divide and give rise to secondary xylem and secondary phloem cells depending upon the position of the division.
*In some roots, pericycle also gives rise to outer protective layer called as periderm. Periderm replaces epidermis.
*Cork cambium gives rise to two layers of cells namely phellem and phelloderm cells. Phellum cells are dead cells which have a thick lining of suberin. These are impermeable to water. Phellogen cells are living cells.
Secondary growth is seen in dicots. Most monocots and herbaceous plants undergo little or no secondary growth.
Cambium is a thin layer of actively dividing cells which are responsible for secondary growth of plants. Cambial cells are undifferentiated cells which have the ability to get differentiated into different types of cells. Two types of cambium present in plants are vascular cambium and cork cambium.
Secondary growth:
Secondary growth is the increase in the girth of the stems and roots of plants. Secondary growth is brought about by lateral meristems, vascular and cork cambiums.
Secondary growth in dicot roots:
Secondary growth is also observed in roots to bring about increase in diameter of the roots.
*Pericycle cells opposite to xylem cells start to divide periclinally. Inner layer of cells gives rise to vascular cambium and outer layer of cells remain as the cells of pericycle.
* Vascular cambium forms a continuous layer around the primary xylem.
*Vascular cambial cells continue to divide and give rise to secondary xylem and secondary phloem cells depending upon the position of the division.
*In some roots, pericycle also gives rise to outer protective layer called as periderm. Periderm replaces epidermis.
*Cork cambium gives rise to two layers of cells namely phellem and phelloderm cells. Phellum cells are dead cells which have a thick lining of suberin. These are impermeable to water. Phellogen cells are living cells.
