TRANSPIRATION

Transpiration is an important, natural process .This topic might seem easy and basic,but is an essential part for any science student.

1. TRANSPIRATION ALI HASSAN VIRK

2. TRANSPIRATION Transpiration  is the process of water movement through a plant and its evaporation from aerial parts, such as leaves, stems and flowers. Water is necessary for plants but only a small amount of water taken up by the roots is used for growth and metabolism. What is transpiration in plants? Transpiration  is the process where  plants  absorb water through the roots and then give off water vapor through pores in their leaves. An example of  transpiration  is when a  plant  absorbs water in its roots.

3. TRANSPIRATION IN PLANTS

4. What causes transpiration ʔ Transpiration  is the loss of water from the plant through evaporation at the leaf surface. It is the main driver of water movement in the xylem.  Transpiration  is  caused  by the evaporation of water at the leaf–atmosphere interface; it creates negative pressure (tension) equivalent to –2 MPa at the leaf surface

5. Cohesion–tension theory of sap ascent is shown . Evaporation from the mesophyll cells produces a negative water potential gradient that causes water to move upwards from the roots through the xylem.

6. Types Of Transpiration THE THREE MAJOR TYPES OF TRANSPIRATION STOMATAL TRANSPIRATION LENTICULAR TRANSPIRATION CUTICULAR TRANSPIRATION TRANSPIRATION   mainly takes place through surface of leaves. It is known as Foliar  transpiration  (more than 90%).

7. STOMATAL TRANSPIRATION Stomatal transpiration : It is the loss of water through specialized pores in the leaves. It accounts for around 80 to 90% of the total  water  loss from the plants.

8. LENTICULAR TRANSPIRATION Type #  2. Lenticular Transpiration: Sometimes water may evaporate through certain other openings present on the older stems. These openings are called Lenticels and the transpiration that takes place through term is known as Lenticular Transpiration. Huber observed in some plants that water lost by lenticular transpiration was about 0.1% of the total transpiration loss. He further noted that coating the bark of the trees reduced the total loss by 20% from total bark surface.

9. CUTICULAR TRANSPIRATION Cuticular Transpiration  – This type of  transpiration  is responsible for the loss of water in plants via the  cuticle . Water vapor directly diffuses through the  cuticle  on leaves and herbaceous stems and escapes to the atmosphere. Type Of Transpiration

10. SIGNIFICANCE OF TRANSPIRATION The significance of transpiration is explained below:  Transpiration helps in the conduction of water and minerals to different parts of the plants. Due to the continuous elimination of water from the plant body, there is a balance of water maintained within the plant.  It maintains osmosis and keeps the cells rigid.  A suction force is created by transpiration that helps in the upward movement of water in the plant

11. Factors Affecting Transpiration in Plants Cellular Factors The cellular factors affecting the rate of transpiration are: The orientation of leaf, The water status of the plant, Structural Peculiarities of the leaf, Total number and distribution of stomata in a leaf.