Plant Growth: Differentiation, Dedifferentiation & Redifferentiation 🌱
1. Differentiation: Becoming Specialized!
Cells from root/shoot tips 🌱 or cambium mature to do specific jobs. Changes happen in:
- 🛡️ Cell walls (e.g., thicken for strength)
- 💧 Protoplasm (inner cell material)
Example: Forming tracheary elements (water pipes 🚰):
- → Lose their protoplasm
- → Grow lignocellulosic walls (super strong & elastic!)
2. Dedifferentiation: Reset Button for Cells! ⏪
Mature cells (that stopped dividing) can regain division ability!
Example: Soft parenchyma cells become:
- 🌿 Interfascicular cambium (between vascular bundles)
- 🪵 Cork cambium (makes outer bark)
Lab term: Dividing parenchyma in tissue culture = callus 🧪
3. Redifferentiation: New Specialists! 🔄
Dedifferentiated cells divide → become new specialized cells.
Examples in trees 🌳:
- 🪵 Wood (from vascular cambium)
- 🧱 Cork (from cork cambium)
Tumor comparison: Chaotic, uncontrolled cell division! ⚠️
4. Open Differentiation: Location = Destiny! 📍
Cells from the same meristem mature differently based on position:
- 🌱 Root tip cells:
- Away from tip → Become root-cap cells (protective hat 🧢)
- At edge → Become epidermis (skin layer 🛡️)
Can you think of more examples? (e.g., leaf cells!) 💭
5. Development: Life Story of a Plant! 🌍
Includes all changes from:
- 🌱 Seed germination → 🍂 Old age
- Covers growth, differentiation, dedifferentiation, redifferentiation
Shown in diagrams (like your Fig. 13.8) for cells, tissues & organs!
NEET Super-Short Notes! 🚨
- Dedifferentiation: Mature cells regain division ability (e.g., parenchyma → cambium)
- Redifferentiation products: Cork, wood in trees 🌳
- Tracheary elements: Lose protoplasm + lignocellulosic walls for water transport 💧
- Open differentiation: Cell fate depends on location (root tip → root cap/epidermis)
- Callus: Dividing parenchyma in labs 🧪
