Meristematic tissue Permanent tissue • Cells divide repeatedly • Cells are undifferentiated • Cells are small and Isodiametric • Intercellular spaces are absent • Vacuoles are absent • Cell walls are thin • Inorganic inclusions are absent • Do not divide • Cells are fully differentiated • Cells are variable in shape and size • Intercellular spaces are present • Vacuoles are present • Cell walls maybe thick or thin • Inorganic inclusions are present Difference Between Collenchyma and Sclerenchyma Collenchyma Sclerenchyma • Living Cells • Contains Protoplasm • Cell walls are cellulosic • Thickening of cell wall is not uniform • Keeps the plant body soft • Sometimes it has chloroplast • Dead cells • Do not have protoplasm • Cell walls are lignified • Thickening of cell wall is uniform • Keeps plant body stiff and hard • Do not have chloroplast . The Tissue System Introduction to Tissue System, Types and Characteristics of tissue System As you have learnt, the plant cells are organised into tissues, in turn the tissues are organised into organs. Different organs in a plant show differences in their internal structure. This part of chapter deals with the different type of internal structure of various plant organs and its adaptations to diverse environments.
A group of tissues performing a similar function, irrespective of its position in the plant body, is called a tissue system . In , German Scientist Julius Von Sachs recognized three tissue systems in the plants. They are: Difference between Fibre and Sclereids Fibre Sclereids • Long cells • Narrow, Elongated pointed ends • Occurs in bundles • Commonly unbranched • Derived directly from meristematic tissue • Short cells • Usually short and broad • Occurs individually or in small groups • Maybe branched • Develops from secondary sclerosis of parenchyma cells Difference between Tracheids and Fibres Tracheids Fibres • Not much elongated • Possess oblique end walls • Cell walls are not as thick as Fibres • Possess various types of thickenings • Responsible for the conduction and also mechanical support • Very