Cell Organisation Cell Organisation in Plantsin Plants

(1) Tissues

(2) Organs & Systems

TissueTissue

2 main tissues type in plants : 2 main tissues type in plants :

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meristematic tissue meristematic tissue

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permanent tissue permanent tissue

Meristematic TissueMeristematic Tissue

Consists of small cells with thin walls, large Consists of small cells with thin walls, large nuclei, dense nuclei, dense cytoplasm and no vacuoles and no vacuoles

Young, active dividing cellsYoung, active dividing cells

Have not undergone differentiation Have not undergone differentiation

Located at the tips of roots and the buds of Located at the tips of roots and the buds of shootsshoots

Permanent TissuePermanent Tissue

Mature tissuesHave undergone differentiationThree types :i. Epidermal tissueii. Ground tissueiii. Vascular tissue

i. Epidermal tissuei. Epidermal tissue

Outermost layerCovers the stems, leaves and roots Most are flat and have large vacuoleWalls are covered with waxy cuticleRoot epidermal cells have long projection called root hairsSpecialised epidermal cells that contain chloroplast are called guard cells

ii. Ground tissueii. Ground tissue

Consists of:Consists of:

i.i. Parenchyma tissueParenchyma tissue

ii.ii. Collenchyma tissueCollenchyma tissue

iii. iii. Sclerenchyma tissueSclerenchyma tissue

Form the bulk of

the plant

iii. Vascular tissueiii. Vascular tissueConsists of:Consists of:

i.i. XylemXylem

ii.ii. PhloemPhloem

Continuously

through the plant

Xylem Xylem

Mainly are xylem vessels joined together end to end, from the roots up to the leaves

No cytoplasm so it enables efficient transport of water and mineral salts

Cell walls are thickened with lignin to provide support and mechanical strength to plants

Phloem Phloem

Mainly are sieve tubes, arranged end to end to form long continuous tube-like structures

Transport organic compounds such as newly synthesised carbohydrates and amino acids from the leaf to other parts of the plant

Organs & SystemsOrgans & Systems

Leaf, stem, root & flower are Leaf, stem, root & flower are

some of the organs in plantssome of the organs in plants

Plants have fewer organs than Plants have fewer organs than

animalsanimals

Systems in plants are not as Systems in plants are not as

specialised as animalsspecialised as animals

Flowering plants have 2 main systems, Flowering plants have 2 main systems,

the root and the shootthe root and the shoot

There is also support system in plants There is also support system in plants

consisting stems and branchesconsisting stems and branches