Respiration is the physiological process in which complete and incomplete oxidation of organic food takes place. In respiration, the oxidation of various organic food substances like carbohydrates may take place. The process of respiration occurs in all living cells of plants and animals and generally called cellular respiration. The energy which produced during the process is used in all the cell and represented by the following chemical equation.
C6H12O6 + 6O26CO2+ H2o + energy (2868kj or 686Kcal)
The main facts associated with respiration are
- Consumption of atmospheric oxygen.
- Release of energy by break down of organic food.
- Liberation of carbon dioxide and a small quantity of water.
- Oxidation and decomposition of reserve food.
Demonstrate the process of transpiration of the bell jar method
Apparatus: Glass bell jar, wooden plate, polythene bag, thread.
Materials: Healthy potted plant
most of the water absorbed is lost in the form of vapor through the ariel parts of the plants into the process called transpiration. Very little water (less than 2%) is used up in various metabolic activities in plants. Most of the transpiration takes place through the leaves known as foliar transpiration. Transpiration may occur through the cuticle, lenticels, stomata, and something bark in some species of plants.
A healthy potted is taken for this purpose. Now the soil surface of the pot is being covered by the polythene bag so that there is no evaporation of water from the moist surface of the soil. Thereafter the potted plant is kept on a wooden plate is being covered over by a ball jar. The margins of the bell are vase lined, so that the atmospheric air may not enter the bell jar. Now covered potted plant is kept in contact with sunlight.
Observation: After some time, the droplets, of water vapor appear on the inner surface of the bell jar.
Result and conclusion: since the bell jar and pot are sealed completely with Vaseline and polythene bag, there is no possibility of water vapor coming inside the apparatus from the outer environment and soli. Thus, the only source of water accumulated on the inner side of the bell jar is the water escaping the ariel parts of the plant kept under the bell jar. This concludes that the water escapes out through ariel parts of plants in the form of water vapor.
- The soil surface of the pot should be covered properly.
- The edge of the bell jar should be sealed properly with the help of Vaseline.
- The experimentative plant should be healthy and well-watered.
- The setup should be kept in contact with sunlight.