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What are permanent tissues? describe different types of permanent tissues. |
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Answer» nt Tissue:Permanent tissues are composed of cells that have lost the power of cell division.They have definite shape and size.Under special circumstances they regain their cell division power.━━━━━━━━━━━━━━━Types of Permanent Tissue:Simple permanent TissueComplex permanent tissue.━━━━━━━━━━━━━━━a. Parenchyma: They're living tissue.They're universal in distribution in plant body.It's a part of GROUND tissue.Its found in mesophyll of LEAVES and endosperm of seeds.They're of three types----Chlorenchyma: They have chloroplasts in them.Aerenchyma: They have oval cells with lot of intracellular spaces containing air Storage Parenchyma: They store sugars, protein granules.b. Collenchyma:The cells are elongated The end of the cells are blunt.The cell wall is made up of celluloseCells may not contain intracellular spaces.Nucleus is prominentPrimary pits are present where walls are uniform in thickness.c.Sclerenchyma:The cells are cpmpactly arranged The cells are deadThe cells don't have chloroplasts.Cells have LIGNIN on their SECONDARY walls━━━━a. Xylem:This tissue conducts waterThey also conduct mineralsConduction is unidirectionalIt also gives mechanical strength to the plant organ containing itb. Phloem:They conduct foodPhloem is INVOLVED in translocation in both directions. |
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