Simple tissues is/are

Explanation

Tissues which are mede up of only one cells are called simple tissues . They are of three types. They are parenchyma , Collenchyma and Sclerenchyma .
1. Parenchyma : It is living tissue . It occupies the major part of the plant body and the cells are isodiametic . They may be spherical , oval , polygonal or elongated in shape .Their walls are thin and made up of cellulose . They have small intercellular spaces . It performs photosynthesis, storage ,secretion , Healing of wounds secretion , Buoyancy by storing air etc.
(2) Collenchyma : It is simple living mechanical tissue , occurs belwo the epidermis of Dicot plants . It consists of cells which are thickened at the corners due to deposition of cellulose , hermicellulose and pectin . The cells are oval or spherical or polygonal in shape and contain chloroplasts . Intercellular spaces are absent . They may be angular or lacunar or lemellar type . They help in assimilation and provide mechanical support to young stems and petiole of a leaf .
(3) Scierenchyma : It is a dead Mechanical tissue , consists of long , narrow cells with thick and lignified cell walls having pits . they are usually dead cells and without protoplasts . Based on the form , structure , it may be either fibres or sclereids .the fibres are thick walled , elongated and pointed cells , gives mechanical support and also used in Jute Industries . The sclereids are spherical , oval or cylindrical , highly thickened dead cells , found in the fruit walls of nuts , pulp of fruits like guave and sapota , seed coats of legumes and leaves of tea. They also -provide Mechanical support to organs .