What are the definitions for parenchyma, collenchyma and sclerenchyma
1. Parenchyma: A type of simple plant tissue composed of living cells that have thin cellulose cell walls and usually retain the ability to divide, allowing for growth and repair in the plant. Parenchyma cells are typically found throughout the plant, serving various functions such as storage, photosynthesis, and secretion.
2. Collenchyma: A type of plant tissue composed of living cells with unevenly thickened primary cell walls, providing flexible support to young growing parts of the plant. Collenchyma cells are elongated and often found beneath the epidermis of stems and petioles, where they provide structural support while allowing for growth.
3. Sclerenchyma: A type of plant tissue composed of dead cells with heavily thickened secondary cell walls containing lignin, providing strong structural support and protection to mature parts of the plant. Sclerenchyma cells are usually rigid and nonliving, serving to strengthen tissues such as vascular bundles and seed coats.