organisation and transpiration in plant

• waxy cuticle - waterproof, protect the leaf
• upper epidermis is transparent(allow sunlight reach to palisade and protective
• palisade mesophyll have chloroplasts, carry out photosynthesis, closely packed
• spongy mesophyll do gas exchange, carry out photosynthesis
• lower epidermis is transparent and protective
• stomata control water loss (with guard cells), take in CO2, and let out O2 + water
• xylem transfer water into spongy mesophyll (transpiration)
• phloem transfer sugar (translocation, dissolved sugar around the plant)
• Transpiration - the loss of water vapour from the stomata in the leaves of plants by evaporation and diffusion.
• Translocation - the movement of sucrose and Aino acids in phloem from regions of production (leaves) to regions of storage or use in respiration or growth
• 1)root hair cell - take up water from the soil2) water drawn up the stem (to xylem tube)3) veins carry water into the leaves (by transpiration steam)4) water evaporated through stomata
• light, temperature, wind and humidity increase the rate of transpiration
• xylem cell wall made of lignin
• xylem cell have no cytoplasm
• cross-walls are absent in xylem
• mineral ions and water flow upward in xylem
• xylem made of dead cells
• phloem cell wall made of cellulose
• phloem made of living cells
• phloem has companion cells (provide energy for translocation with mitochondria) and sieve plates
• glucose flow up and down, transported by phloem
• surface area - more stomata, more evaporation
• light intensity - speed up photosynthesis
• temperature - increase evaporation
• humidity - concentration gradient
• how far the water travel in the capillary tube could calculate the rate of transpiration
• reservoir is used ti reset the potometer