TRANSPIRATION IN PLANT, STOMATA, USE OF TRANSPORT

Transpiration

Transpiration is the evaporating loss of water through stomata of the leaves.

Transpiration is affected by following external factors as

1. Temperature
2.  Light
3. Humidity
4. Wind speed etc.

 It also affected by following plant factor.

1. Number of distribution of stomata 
2. Percent of open stomata
3.  Water status of plant
4.  Canopy structure

The upward transport of water.

Stomata

• Stomata can also function as the exchange of oxygen and carbon dioxide.
• Stomata generally opened in day and closed at night. It has a pair of guard cell which are responsible for opening and closing of guard cell.
• When turgidity of two both guard cell increases the microfibrils stimulates due to which outer wall of cell bulge so the inner thick wall are forced to obtain as a shape as a crescent then stomata are opened.
• When turgidity of guard cells decreases due to loss of water, it becomes shrieked and flaccid and then stomata become closed.
• Usually the lower surface of dorsiventral leaf (dicotyledonous) has greater number of stomata while in isobilateral leaf (monocot) has equal stomata on both surfaces.

Use of transpiration:-

• Transport are used for the following purpose as

 Create a transpiration pull for absorption and transport of water in plant.

1.  Supplies water for photosynthesis.
2.  Transports minerals from the soil to all parts of the plant.
3.  Cools leaf surface, sometimes 10 to 15 degrees by evaporating cooling.
4.  Maintains the shape and structure of the plants by keeping cell turgid.

• Humidity of rain forest occurs due to cycling of water from root to leaf to atmosphere to soil and so on.
• The plant C₄ Photosynthetic system solves this by increasing the availability of CO2 and decreasing water loss. C4 system is more efficient from c3 system by increasing the level of CO2 twice and losses half amount of water.

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