Slide 1: Transportation in Plants What is transportation and why is it required? : What is transportation and why is it required? Transportation is a process which involves movement substances from the source to the sink and vice versa.
As plants are living they have to transfer certain materials to meet their requirements. What do they transport? : What do they transport? Food prepared by the leaves
Some metabolic products
Minerals How do they transport materials? : How do they transport materials? Transportation in plants is carried out by 2 specialized vascular tissues.
These tissues specifically carry out the transportation of food and water.
Transportation o food takes place through Phloem
Transportation of water takes place through Xylem Vascular Tissue : Vascular Tissue Transportation of Water and Minerals : Transportation of Water and Minerals Water and minerals are transported by Xylem.
Xylem consists of two kinds of elements called tracheids and vessels.
Tracheids and vessels of roots, stem and leaves are interconnected.
They form a water conducting channel. Mechanism involved : Mechanism involved Water is lost from the external surfaces of the mesophyll cells of the leaves by evaporation.
The loss of water from a mesophyll cell makes the cell hypertonic to an adjacent cell.
Water from the adjacent cell diffuses into the mesophyll cell by osmosis and this in turn draws water from another adjacent cell into this cell.
Water continues to diffuse from neighboring cells into the adjacent cells.
Finally, water is drawn from the xylem vessels in the veins.
A pulling force is created to pull water up the xylem vessels as a result of the evaporation of water vapour and this is known as Transpirational pull.
Root Force is used for transportation at night as transpiration does not take place. Transportation of Food : Transportation of Food The movement of food from leaves to other parts of the plant is called Translocation.
In plants, phloem Translocates the food and other substances.
Movement of food can take place in both directions depending upon the need with the help of sieve tubes and companion cells. Slide 11: Flow of substances Tissue of a leaf How is Translocation achieved? : How is Translocation achieved? Translocation in the phloem takes place by utilizing energy.
Sucrose is transported using ATP.
With increase in osmotic pressure water moves in.
The pressure moves material from phloem to the required tissue.
So the phloem sap with food will move from leaves to required parts.