What is transpiration? • Transpiration is a process similar to evaporation. • It is the loss of water in plants, especially leaves but also stem, flowers and roots.
Xylem and Phloem • Xylem and phloem make up the big transportation system of vascular plants.
Xylem • Xylem is a vessel which carries water and minerals, from the roots to the stem and leaves. It’s a dead tissue.
Phloem is a vessel which carries glucose and amino acids either from roots to leaves or from leaves to roots. 1)Pith 2)Protoxylem 3)Xylem 4)Phloem 5)Scelerenchyma 6)Cortex 7)Epidermis
How to measure the rate of transpiration? • Potometer is a device used to measure the rate of traspiration of water uptake. Water uptake is to make photosynthesis and transpiration.
Light • During day time stomata remain open and so evaporation of water takes place normally; but at night these stomata are not open with the result transpiration is checked
Humidity • When atmosphere is dry, then transpiration is more, because it receives water readily but when atmosphere becomes moist or saturated, then it can receive no more of water.
Temparature • The rate of transpiration enhances when the temperature surface is not allowed to become saturated.