Tissue in plants

psst i'm too free to post it up =D XP






Tissue in plants is categorized in to two :
Meristematic tissue and permanent tissue.

lets talk about meristematic tissue first.
-thin wall
-large neclei
-dense cytoplasm
-no vacuole
-young, actively dividing cells
-tip of root or bud of shoot.

following by the permanent tissue, it's categorized into 3, which are epidermal, ground and vascular.

Epidermal
-flat, large vacuole
-cuticle to.....
`minimum water loss
`protect it from mechanical injury
`prevent invasion of diseases caused by microorganisms.
-roots hairs to increase area for water absorptionn
-guard cells -open and close of stomata.


Ground
3 of it : parenchyma, collenchyma, sclerenchyma

Parenchyma
-all organs of plant
-thin primary walls
-large vacuole
-store sugar and starch
-give support and shape to herbaceous plant

Collenchyma
-unevenly thickened walls *especially at corners
-support non woody, young stems and petioles

Sclerenchyma
-cell wall thickened by lignin, may be dead
-give support and mechanical strength to mature regions of plants


Vascular
Xylem and phloem


Xylem
-From roots to leave
-no cytoplasm enable it to....
`efficient transport of water annd dissolved mineral salts from roots
-wall thickened by lignin
`support
`mechanical strength

Phloem
-sieve tubes (tube like)
-newly synthesised carbohydrates, and amino acids in leaf transport by it