🌿 Master Plant Support Tissues Notes |Free Interactive Quiz on Parenchyma, Collenchyma & Sclerenchyma

🌱 Support in Plants – Easy Notes

Plants need support to stand upright, bear weight, resist wind, and transport water & food. Supporting tissues are: Parenchyma, Collenchyma, and Sclerenchyma. Xylem & phloem also help indirectly.

1️⃣ Parenchyma

Found in epidermis, cortex, and pith.
Cells are thin-walled, living and can store water.

Turgor pressure:

Vacuole fills with water → pushes cell wall → keeps plant parts rigid.
Helps in support of herbaceous (non-woody) plants.

Special feature: Tonoplast membrane controls ion movement → water enters vacuole → turgidity.

👉 Function: Provides support in soft tissues through turgor pressure.

2️⃣ Collenchyma

Found in young stems, leaf stalks (petioles), and along veins of leaves.
Cells: Living, elongated, no secondary walls.
Cell walls thickened at corners (extra cellulose deposition).
Can stretch and elongate with the growing organ.

👉 Function: Provides support + flexibility to young growing parts before secondary growth starts.

3️⃣ Sclerenchyma

Cells: Dead at maturity, with thick secondary walls, full of lignin (makes them very hard).
Provides mechanical strength.

Types:

Fibres (Tracheids) → long, narrow, found in xylem & bundle caps; give tensile strength.
Sclereids → short, irregular; found in seed coats (e.g., nuts, pears); provide hardness & protection.
Vessels (Tracheae) → long tubes joined end-to-end; conduct water in xylem and give support.

👉 Function: Provides rigidity and hardness to mature plant parts.

🌟 Quick Comparison Table

Tissue	Nature	Wall Type	Location	Function
Parenchyma	Living cells	Thin primary wall	Soft parts (cortex, pith)	Turgor pressure → soft support
Collenchyma	Living cells	Primary wall thick at corners (cellulose)	Leaf stalks, veins, young stems	Support + flexibility
Sclerenchyma	Dead cells	Thick, lignified secondary wall	Seed coats, xylem, nutshells	Rigidity, strength, protection