Essay On Transpiration

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The purpose of this lab was to learn about transpiration and to determine which conditions would decrease water loss in a plant the fastest. Transpiration is the process of water traveling through the plant to allow nutrients in and to cool the plant. The hypothesis tested: If light and heat, humidity, wind, and a controlled environment (where there is no affecting outside force) is applied to a stem then the water pressure will decrease due to transpiration. Pressure will decrease the greatest in light and heat because water will be lost due to evaporation. Pressure will decrease in wind because the pressure on the stem will affect the amount of water being lost. Pressure will decrease in the controlled environment because there will be little change in water levels. Pressure will decrease the least in humidity because water is being added therefore adding more water thus creating more force against the sensor. The data collected from this lab refutes this hypothesis because the results were unexpected.
In a similar transpiration lab, performed by an AP student, the results showed that controlled was the fastest, wind the second, light and heat the third, and humidity the slowest. These results occurred because all four environments played a role in increasing evaporation which therefore increased the rate of evaporation. In the controlled environment, the room temperature helped increase the rate of evaporation (1.67mL/m²). In the wind environment, the blowing of air on the leaves increased the rate of evaporation (0.76 mL/m²). In the light and heat environment, the heat hitting the plant increased the rate of evaporation therefore increasing amount of water being transpired (0.93 mL/m²). In the humidity environment, the moist ...

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...y that the decrease in pressure is due to the rate of evaporation occurring at the same time. The lab was performed very well and had little to no errors in the procedure due to the practice run that was done the class before.
Possible Errors Include:
• If any air bubbles were present in the tube the results would be inaccurate
• Inability to measure the temperature inside the bag for the experiment on humidity
• Miscalculations on the weight and SA of the leaves
• Miscalculations on the slope, averages, and equation
• Placing the connector lower than the syringe

Improvements to be Added Include:
• Measure temperature inside the bag and see how the temperature affects rate of transpiration
• Weight leaves more than once for accurate weight
• Double check all math calculations
• Write down a reminder to make sure the connector is placed higher than the syringe

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