Petiole Discussion

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Discussion 1. Typically in these types of experiments, the leaf petiole is cut is a way so that there is a sufficient length to insert in the pressure chamber cover. The petiole should be cut as close to the shoot as possible. Because we did not cover the plants in a plastic bag, we had to work extra quickly to avoid transpiration. As long as the petiole remains intact, re-cutting the petiole has no influence on the pressure chamber and the point at which fluid starts to flow out can be clearly observed. 2. In some cases, like in incipient plasmolysis, the pressure potential is equal to 0. Here, we would only need to know what the osmotic potential is to find the water potential. This method only works for non-transpiring leaves or shoots,…show more content…
Plants that have stress have a more negative water potential than non-stressed plants as they have a high affinity for water. Because there is a low concentration of water outside, the water inside will flow from areas of high to low concentrations. 4. Some mistakes in this experiment may have been the fact that the plant started to transpire too quickly, which would give the incorrect data. For many of us, it was the first time observing this transpiration and therefore we may have recorded the data too early or too late. Other problems may have been reading the pressure incorrectly or not using the best available…show more content…
We saw that the pressure bomb was a useful tool in measuring the water potential as a qualitative value without even looking at the solute potential. A problem in this experiment may have been the fact that the plant started to evaporate earlier than expected, which gave the incorrect data. There is a chance that we did not interpret the readings for the pressure bomb as well as the transpiration as accurately as we could have. The pressure bomb method was able to give us, in MPa, the pressure that is needed for a sap to be released from the xylem. We saw that the pressure needed for the sap to flow out was lower for the watered plants when compared to the water-stressed plants, as we would expect. By comparing our data to four other groups, it was clear that our data was similar. This indicates that we ran the experiment successfully and recorded reliable and accurate

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