3. Cells of common features join together to
perform a special function.. These group of cells
are called tissues. Tissues seen in plants are
called plant tissues.
Plant Tissues
4. Tissue formed of same kind of cells with thin cell wall. It
seen in soft parts of plants. Cell wall is made up of cellulose and
calcium pectate.
Paranchyma
5. Storage of reserve food materials.
Storage of water in succulent plants.
Helps in respiration and secretion.
Air storage, buoyancy and gas exchange in water plants.
Helps in regeneration and wound healing by meristamatic
activity.
Functions of parenchyma
6. Collenchyma tissue of similar cells with thickened cell
walls only at the corners. The corners of the cell walls become
thickened due to the deposition of substanes like suberin,
pectin, cellulose etc.
Collenchyma
7. Serves an the chief supporting tissue.
Protect leaves from tearing.
Prevents the bending and breaking of stems.
Gives great flexibility to plant organs.
Some collenchymas possess chloroplast and carryout
photosynthesis.
Occasionally it act as a meristemm during secondary
thickening.
Functions of collenchyma
8. Tissue formed of thick walled cells, thickness is due to the
deposition of a substance called lignin. Hard plant parts are
made up of sclerenchyma cells. Sclerenchyma consist of two
types namely, fibres and sclerids.
Sclerenchyma
9. Serve as a mechanical tissue.
Protect plant, body from damages, physical pressures etc.
Xylum fibres help the conduction of water
Fibrous sclerenchyma of fruits and seed help in dispersal of
seeds.
Sclereids of some nuts from a hard protective cell.
Functions of Sclerenchyma
10. Xylum tissue is formed of elongated cells. These cells
unite together and are seen as pipes. Water and minerals absorbed
by the roots reaches the leaves through these pipes. Due to the
deposition of lignin, the cells become hardened.
Xylum
11. Conducts water and solutes from roots to stem.
Serve as a supporting mechanical tissue.
Forms wood.
Xylem parenchyma stroes, water starch, fat etc.
Ray parenchyma brings about the radial conduction of water
and solutes.
Functions of xylum
12. Phloem tissue formed of elongated cells.They are
formed as pipe like structure.The food prepared in the leaves
reaches the different parts through these pipes.
Phloem
13. Functions of phloem
Translocation of organic nutrients.
Phloem fiber s provide mechanical support and elasticity.
Storage of organic nutrients and other substances.
14. Reference
Angiosperm Antony Reproductive botany And palynology
IV th Semester Degree Programme – Kerala
VIII th Science text book IInd Part
