The variations of plant tissues according to the structure and functions.
Some parts of a plant are very hard while others are soft or spongious. These variations are specialized to perform the plant's particular functions. Tissues are group of cells of one type or different types which are specialized to perform a paricular function and have common origin. Plant and animal bodies are comprised of several tissues.
PLANT TISSUES
Plant tissues are categorized into two main groups.
* Permanent tissues
* Meristamatic tisues
1. PERMANENT TISSUES
a. Simple permanent
* Parenchyma
* Collenchyma
* Sclerenchyma
b. Complex Permanent
* Phloem
* Xylem
SIMPLE PERMANENT TISSUES
PARENCHIMA TISSUE
* Consists of living cells.
* Cells are spherical or elongated in shape.
* Thin cell wall is made up of cellulse.
* There are intercellular spaces among these cells.
(Eg: pallisade parenchyma, spongy parenchyma, food stored
parts of the plant)
COLLENCHIMA TISSUE
* Consists of living cells.
* Cells are elongated in shape.
* Cell corners are thickend with cellulose.
* Intercellular spaces are not prominent.
(Eg: outer parts of stems, midrib of leaves, tender stems contain chloroplasts)
SCLERENCHIMA TISSUE
* When get matured cells become non living.
* Lignin deposited on the cell walls.
* Provides mechanical strenth to the plant.
* Absense of intercellular spaces.
(Eg: fibres, sclerids)
COMPLEX PEMANENT TISSUES
PHLOEM TISSUE
* Four types of cells can be seen in phloem tissue.( Sieve tube
elemants, Companion cells, Phloem parenchyma cells,
Phloem fibres)
* Phloem fibers are non living.
* Main function is translocation of food throughout the plant.
XYLEM TISSUE
* Four types of cells can be seen in xylem tissue.( Trcheids,
Vessel elemants, Xylem parenchyma cells, Xylem fibres)
* Xylem parenchima cells are only living cells in the tissue.
* Main function is conduction of water and mineral salts.
* Provide mechanical support.
2. MERISTEMATIC TISSUES
* Apical meristem
* Lateral meristem
* Inter calory meristem
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