The water loss from leaves through stomata Essay Example for Free

The water loss from leaves through stomata Essay Analysis conclusion As you can see from the table of results leaf 4 lost the least amount of water. Leaf 4 lost the most water because it had no petroleum jelly covering the stomata. This meant water vapour could diffuse from the leaf. My prediction was correct. However I also stated that leaf 3 would lose just as much water as leaf 1. I was incorrect. This was an anomalous result. Leaf 1 lost the least amount of water because it was covered in petroleum jelly. The water vapour, which is formed, was not allowed to diffuse into the air because petroleum jelly is non-permeable. My prediction was correct. This was be However I also stated that leaf 3 would lose as much water as leaf 4 but I was incorrect as leaf 4 lost more water. This was an anomalous result. In the result there are no patterns or trends. In the experiment I discovered that if petroleum jelly was put on the underside of the leaf, it would stop more water vapour escaping than if petroleum jelly was added to the top of the leaf or if none was put on at all. This is because at the underside of the leaf are stomata. There is water loss only through stomata. This occurs when heat from the sun causes water to evaporate from the surface of the cellulose wall. The water vapour formed then diffuses into the air. Stomata are found only on the underside of the leaf. When the underside of the leaf is covered in petroleum jelly the water vapour cannot diffuse through it into the air because it is non-permeable. This prevents the loss of water. When petroleum jelly is added to the top of the leaf (or if none is put on the leaf at all) then water vapour inside the leaf can escape through the stomata, which are found only under the leaf. The explanation is correct because there is proof of this on the graph and in the table of results Evaluation There were enough results obtained to draw a firm conclusion. The results were accurate and reliable. In the experiment however there were anomalous results of all of the leaves. Leaf 1 and 3 should have both lost the same amount of water and leaves 2 and 4 should have lost the same amounts of water. This may have happened because the leaves may have not have had the same amount of water in them at the beginning of the test. Also the leaves themselves may not have had equal surface areas. Also the amount of petroleum jelly may not have covered the whole leaf (this may have given unfair advantage to one of the leaves). The readings were not repeated when any of the values did not fit in with the pattern. The readings, which were taken, were far enough to make a firm conclusion. However the experiment could have improved. In the experiment the size and mass of the leaves were approximately the same but more accurate measurements could have been such as weighing the leaves at the start on an electro balance (before the petroleum jelly was added) to make sure the leaves had the same mass. Also the perimeter of the leave could have been measured to make sure the surface area was the same. To make the test more accurate it couldve been done twice. Also when petroleum jelly was added there may have been gaps in between (so water vapour could have diffused), this should have been checked. To take the experiment further it could have been repeated with different specie of leaf to see if the results were the same.