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Plant Tissues -for SSC-CGL
ABOUT ME Name: Aman Srivastava o B.tech in Electronics & Communication (I.E.T Lko) Cleared SSC-CGL 2016 pre + mains Follow me on Unacademy Please rate ,review & share
Plant tissues are of two main types, viz. 1 - Meristematic Tissue:-in which cells keep on 2- Permanent Tissue: the cells of meristematic meristematic tissue and permanent tissue. dividing are called meristematic tissue tissue divide to a certain extent, after that they become specialized for a particular function. This is called differentiation. After differentiation, the cells lose their capability to divide and the tissue becomes permanent tissue.
Meristematic Tissue: Apical Meristem:- is present on root apex, stem apex, leaf buds and flower buds. They are responsible for growth in length, i.e. primary growth. Lateral Meristem is present along the side of the stem. They are responsible for growth in girth, i.e. secondary growth. . Intercalary Meristem: is present at the base of leaf or internodes. They are present on either side of the node.
Simple Permanent Tissue is composed of similar types of cells. Simple permanent tissues are of three types, viz. parenchyma, collenchyma and sclerenchyma. 1) Parenchyma: have thin cell wall. They are loosely packed; with lot of intercellular spaces between them. Parenchyma makes the largest portion of a plant body, mainly works are packing material in plant parts. . The main function of is to provide support and to store food. . In some plant parts, parenchyma has chlorophyll as well. In that case, parenchyma carries out photosynthesis and is then termed as chlorenchyma. In aquatic plants, large air cavities are present in parenchyma. This provides buoyancy to the plant, and then the parenchyma is known as aerenchyma.
INTERCELLULAR SPACES 8 INTERCELLULAR SPACES CHLOROPLAST /L Types of Parenchyma (A & B) C Chiorenchyma D. Aerenchyma.
Simple Permanent Tissue 2) Collenchyma: The cell wall is thickened at corners. Intercellular spaces are very few. Collenchymas provides some degree of structural rigidity with flexibility. Collenchymas is present in leaf stalk; below the epidermis. Due to this, the leaf talk can easily bend but does not break. 3) Sclerenchyma: The cell wall is highly thickened all around The cells are dead and intercellular space is absent. Sclerenchyma provides structural rigidity to plant parts. Bark and the coconut husk is composed of sclerenchyma. .
T.S. L.S Collenchyma
Thick cell wall of Longitudonal view of sclerenchvma cells clerenchyma cells
Complex Permanent Tissue: is composed of different types of cells. Complex permanent tissues IS are of two types, viz. xylem and phloem. Xylem and phloem together make the vascular bundle in plants. Xylem: Xylem is composed of trachieds, vessels, xylem parenchyma and xylem fibres. The cells of xylem are dead; except the cells of xylem parenchyma. Trachieds and vessels are tubular structures and thus they provide a channel for conduction of water and minerals. Xylem fibre provides structural support to the tissue. Xylem parenchyma stores food. .