Getting to Know Plants

Herbs: small, soft, green stems (tulsi, mint, wheat). Shrubs: medium-sized, woody stems, branches near base (rose, cotton, mehendi). Trees: tall, thick woody trunk, branches high up (mango, neem, banyan). Climbers: need support to grow (money plant, pea, grapevine). Creepers: grow along ground (pumpkin, watermelon).

Taproot: one main root with smaller branch roots (mango, rose, mustard). Fibrous roots: bunch of thin roots, no main root (grass, wheat, rice, maize). Functions: absorb water and minerals from soil, anchor plant, store food (carrots, radish = modified taproots). Root hair cells increase surface area.

Functions: supports leaves and flowers, transports water and nutrients. Conducting vessels: xylem (water up) and phloem (food down). Modified stems: potato (underground), ginger (rhizome), onion (bulb), cactus (stores water). Experiment: put celery/white flower in coloured water — colour travels up stem through xylem.

Leaf structure: blade (lamina), petiole (stalk), midrib, veins (network or parallel). Stomata: tiny pores on leaf surface for gas exchange. PHOTOSYNTHESIS: leaves use sunlight, water (from roots), CO₂ (from air) to make glucose + oxygen. 6CO₂ + 6H₂O + sunlight → C₆H₁₂O₆ + 6O₂. Only green plants can do this — they are PRODUCERS.