Investigation Into The Rate of Water Uptake By Transpiration Essay Example

Investigation Into The Rate of Water Uptake By Transpiration Essay The rate of water uptake in a plant is directly proportional to the surface area of the leaves on the plant. As the surface area is reduced, the time taken for the water to travel up the stem over the same distance will increase.Background Knowledge:Plants add a considerable volume of moisture to the atmosphere. After absorbing water through their roots, the water travels up the stem to the leaves where over 99% of the absorbed water is lost through the leaves by a process named transpiration. The Sun provides the energy required to turn the water in the leaves into a vapour, causing it to diffuse out of the plant and into the atmosphere. Water evaporates from the leaves and causes a force that pulls the water up the stem. The water travels through the vessels in the vascular bundles and this flow of water is called the transpiration stream.Vascular tissue is made up of xylem and phloem. These tissues are concerned with the translocation (transport) of water and nutrients around the plant. Xylem carries mainly water and mineral salts, whereas phloem carries mainly organic solutes in solution, for example sugars. As the vascular tissue forms a transport system around the plant, a large, complex body will develop.Xylem fibres are thought to have originated from tracheids (single cells that are elongated and lignified), however they are shorter and narrower than tracheids. Overlapping walls are present at the end of the xylem. Phloem resemble xylem as they also have a tubular structure that is modified for translocation. The tubes are composed of living cells, and there are five different cell types: sieve tube elements, companion cells, parenchyma, fibres and schlerids.See Figure 1a that shows how phloem and xylem play an important role in transpiration. Figure 1b shows how gaseous exchange occurs in leaves..Transpiration is the evaporation of water from leaves; therefore any change that increases or reduces evaporation will have the same effect on transpiration. The following variables can affect the rate of transpiration.Light intensity Light itself does not directly affect transpiration, but in daylight the stomata of the leaves are open. This allows the water vapour in the leaves to diffuse out of the plant into the atmosphere. At night, when the stomata are closed, transpiration rates are greatly reduced. Generally, transpiration speeds up when the light intensity increases as the stomata respond to changes in the light intensity.Humidity If the air is very humid it can accept very little from the plants and therefore transpiration slows down. In dry air, the diffusion of water vapour from the leaf to the atmosphere will be rapid.Temperature Warm air can hold more water than cool air. Thus, transpiration will take place more rapidly in warm air. When the sun shines on the leaves, they will absorb heat as well as light. This warms them up and increases the rate of transpiration.Air movements In still air, the region surrounding a tr anspiring leaf will become saturated with water vapour so that no more can escape from the leaf. In these conditions, transpiration will slow down. In moving air, the water vapour will be swept away from the leaf as fast as it diffuses out. This will increase the rate of transpiration.Leaf surface area A reduction in leaf surface area will reduce the rate of transpiration, as there will be a smaller distribution of stomatal pores.Cuticle The thinner the leaf cuticle layer, the greater the rate of cuticular transpiration. The upper surface of dicotyledonous leaves generally has a thicker cuticle compared with the lower layer. Thick, waxy cuticles can virtually eliminate cuticular transpiration and the shine reflects solar radiation.Stomata The greater the number of stomata per unit area, the greater the rate of transpiration. Plants showing xeromorphic adaptations usually have reduced numbers of stomata. In dicotyledonous plants, the lower leaf surface usually possesses more stoma ta than the upper surface.In order to make this a fair experiment, the following precautions need to be taken. My experiment will be conducted inside a science lab at school, away from the windows. The light intensity should not change during the experiment. The humidity of the air will not change within the laboratory. There is a thermostat located within the laboratories, and therefore the temperature should remain constant. There is an air conditioning unit installed in order to control the temperature, but it should not affect my experiment. I am unable to change the thickness of the cuticle, but I will use the same plant for each attempt. I will also not be able to change the number of stomata present on the leafs surface; therefore I will assume that there will be an equal spread of stomata over each and every surface.All of these are factors that may affect the experiment, but hopefully I will be able to conduct a fair test.Plan:For this experiment I will be using a simple po tometer (from pot meaning drink and meter meaning measure) to measure the rate of water uptake in a plant, and how this rate is affected by leaf surface area.Apparatus:1. Privet plant (used as it has many leaves that may be easily counted and that are about the same size)2. Capillary tubing with water used as a meniscus scale (each mm on the scale is equivalent to 1mm? of water I will use 50mm)3. Beaker of water4. Stand (this will help to support the plant)5. Stop clock (showing minutes, seconds and 1/10th second)See Figure 2 that shows how I will set up the apparatus. It must be secure on the tabletop. This is so that it is not dangerous in any way to anyone else.Method:1. I will cut a privet plant underwater about 3cm up the stem. This will remove any blockages in the xylem from when the plant was cut previously. The xylem must not be crushed, so the plant will be cut at an angle with a sharp blade. The plant will be cut underwater to prevent any air bubbles getting into the xyle m, as this may affect the final results.2. I will submerge the capillary tube in the same water bowl. It will be attached to the plant, making sure no air bubbles are inside. I must make sure the open end of the capillary tube is also underwater so that all of the apparatus can be lifted out.3. This will make sure that the whole system is completely airtight. When the plant transpires, water will be pulled along the tubing. I will allow the apparatus to equilibrate for about 5 minutes.4. I am going to introduce an air bubble into the system. Holding the tubing out of the water for a minute can do this.5. I will make sure the bubble starts at the correct place on the scale, and time how long it takes for the bubble to move 50mm. This can be achieved by allowing the bubble to pass from no.1 to no.5 on the scale. Afterwards I will move the bubble back with the water.6. I will note the times in the table.7. I am going to repeat each attempt three times. This should give me enough readin gs to be able to calculate the mean average if need be. Each measurement will be taken from the same point of the bubble.Figure 3 shows how I am going to make sure the bubble is at the correct place on the scale. The bubble can be moved backwards by opening the tap from the reservoir and allowing more water in.8. Ten leaves will be removed and the surface area of the leaves calculated. The test will be repeated again. Each time I will remove ten leaves, and the last test I conduct will have only ten leaves on the plant.9. I will be conducting a practice experiment, with just one reading for each set of leaves that I remove. This will appear in my results as 1st attempt.10. Three other readings will be taken with another branch of the same privet plant. It is the surface area of this second branch that I will record. The surface area will be used to compare how the rate of uptake will change against the number of leaves I will be removing.Safety Procedures:* I will not be using any h azardous substances, but I must be careful not to spill any water on the workbench.* The sharp blade must be used with care, as it is very sharp and fingers can be cut easily. When they are not being used, the blades must be kept inside their box so that other people will not hurt themselves if they are left lying around.* I will not break any branches off the privet hedge that I will not be using for the experiment. This means that I will not be disturbing any organisms unnecessarily that live on the plant.* The apparatus must be positioned steadily on the surface. It is quite bulky, and I must be careful not to knock it over and spill the water.Predictions:I predict that if the surface area of the plants leaves is reduced the rate of uptake will slow down. This is because the number of stomata will be reduced, and transpiration rates will be reduced. I predict that the rate will decrease in proportion to the number of leaves removed, for example if the number of leaves is reduced by 50%, the rate of uptake will be reduced by 50%. The rate of transpiration is directly proportional to the surface area of the leaves on the plant. This is assuming that all other variables will remain constant. I am assuming that there will be an equal distribution of stomata on all of the leaves, and also that the surface area of each set of 10 leaves I remove will be approximately the same. For example, each set may have a combined surface area of 50 cm?.See Figure 4 that shows how I predict the rate of uptake will change. As I am unsure of the rate at present, I have left the axis unlabelled and shown only the general trend.Method:This was carried out as stated earlier, with no changes made to the original plan. The first attempt was carried out on a different branch to the other three attempts. This was to test the experiment, and it also gave me an approximate time of the whole experiment.Results:Time of Water Uptake (seconds)Number of Leaves1st Attempt2nd Attempt3rd Attempt 4th Attempt1003623753673849042342743448580409423423409703754634234716045848548049750505561543609404046945746843040978160970420704892704735101612962862943I choose to display the rate of water uptake (mm/second) rather than the time taken to travel 50mm as this gave a more accurate indication of how quickly the bubble travelled:50mm = Rate in mm/secondTime taken (s)Rate of Water Uptake (mm/second)Number of Leaves1st Attempt2nd Attempt3rd Attempt4th Attempt1000.1380.1330.1360.130900.1180.1170.1150.103800.1220.1180.1180.122700.1330.1070.1180.106600.1090.1030.1040.101500.0990.0890.0920.082400.1240.0720.0870.073300.1220.0640.0820.071200.0710.0560.0710.068100.0310.0520.0580.053I have plotted the results graph in a conventional way, with the number of leaves starting at 10 and leading up to 100. Although I carried out the experiment from 100 downwards, it seemed logical to plot the results the other way around. This shows the pattern clearly. I did carry out an experiment for 0 leaves, but the rate was too slow, and it is for this reason that I have not displayed the results I found.Figure 5 shows the results. The rates are shown, as these are easily comparable numbers to work with. They give a more accurate view of how quickly the bubble travelled over 50mm.It is clear from the graph that there is an increase in the time taken as the number of leaves decreases. The rate slows down, and the bubble travels more slowly. This is due to the decreasing rate of transpiration. As the number of leaves decreases, the numbers of stomata decrease and the rate of transpiration slows down. As the transpiration rate slows down, the rate of uptake is slowed down to prevent further water loss.Conclusion:My results show that the rate of uptake slowed down as more leaves were removed, and as the surface area of the plant decreased.The first attempt proved very useful, as I did not anticipate that the air-conditioning unit would affect my results as much as it did. The graph that I drew with the rates of water uptake shows clearly all four attempts. From this, I can see that the mean average rate for 100 leaves was 0.134mm/second. The mean average rate for 10 leaves was 0.049mm/second.This experiment has matched my predictions, however not quite as well as I had hoped. I had predicted that when the leaf surface area was reduced by 50%, the rate of water uptake would decrease by 50%. This was not the case. The mean rate of transpiration for 50 leaves is not 50% of the mean average for 100 leaves; it is nearer to 67%. The mean rate of water uptake for 50 leaves was 0.091mm/second.The anomalies from the first attempt have been marked as A, B and C. A and B have higher rates of water uptake than expected. This was because the air conditioning unit came on and moved the air around the leaves more quickly, thus causing the plant to transpire more quickly. C also has a higher rate of water uptake than expected due to the light intensity changing. The first attempt was co nducted in front of a window, and when the Sun came out the light intensity increased. The other three attempts were not conducted directly in front of a window. The time taken to transpire increases as the leaf surface area decreases. This is due to the removal of stomatal pores that allow the plant to exchange gases and water vapour. To prevent dehydration, the pores close to prevent further water loss and the rate of transpiration slows down.There was only one other anomaly throughout the whole experiment. This has been marked on the results graph as D, and occurred on the fourth attempt for 90 leaves. Although I had moved the apparatus away from the air-conditioning unit previously, on this occasion the breeze still affected my results. It did not disturb the air surrounding the leaf, as it did previously. This would have increased the rate of uptake. The cooler air meant that transpiration slowed down, having a direct effect on the rate of water uptake.The rate of transpiration was fastest for all four attempts when there were all 100 leaves on the plant, and slowest when there were only 10 leaves on the plant. All of the conditions were kept constant; therefore it was the stomatal quantity that affected the rate of transpiration.It was important that I measured the rate of uptake and not the rate of transpiration. Transpiration is very difficult to measure. The volume of water taken up is far greater than the volume of water given out through transpiration. This is because a large volume of water is used by the plant for turgidity, photosynthesis and other biological functions such as hydrolytic processes.My results shown in Figure 5 are almost linear. This matches my predicted graph, and is due to the proportion of leaves removed at each time. Although I did not realise at the time, I was removing approximately 10% of the leaves each time. This was purely coincidental, and was only discovered when I plotted the surface area against the number of leaves in Figure 6. The trend shown in Figure 5 is mirrored in Figure 6. This pattern may also have followed my predictions for another reason. The stomatal distribution across the leaf surface area may have been equal across all 100 leaves. If this was true, the total number of stomatal pores would have decreased in proportion to the number of leaves too.Evaluation:The first attempt was affected by the air-conditioning and light intensity. However, this was my practise experiment and I decided to then use another branch, approximately the same size for the next three attempts. All of the surface area calculations shown in Figure 6 are for the second branch. I made sure that the air-conditioning would not start during the second experiment, and also that I did not set up the apparatus next to another window. When the Sun shone through the window, it was very bright and the light intensity increased. I did not realise that these two factors could affect the rate of transpiration as much as they did.I did not take into account the stomatal distribution in either of my two experiments. This would have been an interesting variable to look at, however I found that I was short on time. I would have liked to have looked at the lower epidermis underneath a microscope, and made an approximate stomatal count. I could have seen if they were evenly spread, and if not, still made an estimated rate of uptake from my other results.My results were very pleasing overall. They followed my predicted trend and I have been able to see why, due to measuring the total surface area of the second branch. I have accounted for my anomalies as the experiment was affected by factors beyond my control. I had not realised that the air-conditioning and positioning of the apparatus would affect the experiment in such an extreme fashion. Factors such as light intensity and the temperature of the surrounding air may only change slightly, but have a larger effect on the overall experiment.I would have liked to repeat the experiment again, so that I could obtain more results. This would give me a more significant mean average, and I would have been able to leave out the anomalies in the analysis. A source of error may have been counting the number of leaves rather than the surface area. Nevertheless, it turned out that I was removing the leaves by nearly 10% each time.I would improve the experiment by measuring the stomatal distribution next time. This will allow me to calculate a more significant rate of uptake by calculating how much water is taken in through each stomatal pore. I could then estimate how much water should be taken in. If I was able to calculate the transpiration rate as well, I would be able to work out how much water was being used within the plant.Generally, this experiment was conducted well. The anomalies were not large enough to change the trend in any way, and the overall results were beneficial in proving the hypothesis correct. Investigation Into The Rate of Water Uptake By Transpiration Essay Example Investigation Into The Rate of Water Uptake By Transpiration Essay The rate of water uptake in a plant is directly proportional to the surface area of the leaves on the plant. As the surface area is reduced, the time taken for the water to travel up the stem over the same distance will increase.Background Knowledge:Plants add a considerable volume of moisture to the atmosphere. After absorbing water through their roots, the water travels up the stem to the leaves where over 99% of the absorbed water is lost through the leaves by a process named transpiration. The Sun provides the energy required to turn the water in the leaves into a vapour, causing it to diffuse out of the plant and into the atmosphere. Water evaporates from the leaves and causes a force that pulls the water up the stem. The water travels through the vessels in the vascular bundles and this flow of water is called the transpiration stream.Vascular tissue is made up of xylem and phloem. These tissues are concerned with the translocation (transport) of water and nutrients around the plant. Xylem carries mainly water and mineral salts, whereas phloem carries mainly organic solutes in solution, for example sugars. As the vascular tissue forms a transport system around the plant, a large, complex body will develop.Xylem fibres are thought to have originated from tracheids (single cells that are elongated and lignified), however they are shorter and narrower than tracheids. Overlapping walls are present at the end of the xylem. Phloem resemble xylem as they also have a tubular structure that is modified for translocation. The tubes are composed of living cells, and there are five different cell types: sieve tube elements, companion cells, parenchyma, fibres and schlerids.See Figure 1a that shows how phloem and xylem play an important role in transpiration. Figure 1b shows how gaseous exchange occurs in leaves..Transpiration is the evaporation of water from leaves; therefore any change that increases or reduces evaporation will have the same effect on transpiration. The following variables can affect the rate of transpiration.Light intensity Light itself does not directly affect transpiration, but in daylight the stomata of the leaves are open. This allows the water vapour in the leaves to diffuse out of the plant into the atmosphere. At night, when the stomata are closed, transpiration rates are greatly reduced. Generally, transpiration speeds up when the light intensity increases as the stomata respond to changes in the light intensity.Humidity If the air is very humid it can accept very little from the plants and therefore transpiration slows down. In dry air, the diffusion of water vapour from the leaf to the atmosphere will be rapid.Temperature Warm air can hold more water than cool air. Thus, transpiration will take place more rapidly in warm air. When the sun shines on the leaves, they will absorb heat as well as light. This warms them up and increases the rate of transpiration.Air movements In still air, the region surrounding a tr anspiring leaf will become saturated with water vapour so that no more can escape from the leaf. In these conditions, transpiration will slow down. In moving air, the water vapour will be swept away from the leaf as fast as it diffuses out. This will increase the rate of transpiration.Leaf surface area A reduction in leaf surface area will reduce the rate of transpiration, as there will be a smaller distribution of stomatal pores.Cuticle The thinner the leaf cuticle layer, the greater the rate of cuticular transpiration. The upper surface of dicotyledonous leaves generally has a thicker cuticle compared with the lower layer. Thick, waxy cuticles can virtually eliminate cuticular transpiration and the shine reflects solar radiation.Stomata The greater the number of stomata per unit area, the greater the rate of transpiration. Plants showing xeromorphic adaptations usually have reduced numbers of stomata. In dicotyledonous plants, the lower leaf surface usually possesses more stoma ta than the upper surface.In order to make this a fair experiment, the following precautions need to be taken. My experiment will be conducted inside a science lab at school, away from the windows. The light intensity should not change during the experiment. The humidity of the air will not change within the laboratory. There is a thermostat located within the laboratories, and therefore the temperature should remain constant. There is an air conditioning unit installed in order to control the temperature, but it should not affect my experiment. I am unable to change the thickness of the cuticle, but I will use the same plant for each attempt. I will also not be able to change the number of stomata present on the leafs surface; therefore I will assume that there will be an equal spread of stomata over each and every surface.All of these are factors that may affect the experiment, but hopefully I will be able to conduct a fair test.Plan:For this experiment I will be using a simple po tometer (from pot meaning drink and meter meaning measure) to measure the rate of water uptake in a plant, and how this rate is affected by leaf surface area.Apparatus:1. Privet plant (used as it has many leaves that may be easily counted and that are about the same size)2. Capillary tubing with water used as a meniscus scale (each mm on the scale is equivalent to 1mm? of water I will use 50mm)3. Beaker of water4. Stand (this will help to support the plant)5. Stop clock (showing minutes, seconds and 1/10th second)See Figure 2 that shows how I will set up the apparatus. It must be secure on the tabletop. This is so that it is not dangerous in any way to anyone else.Method:1. I will cut a privet plant underwater about 3cm up the stem. This will remove any blockages in the xylem from when the plant was cut previously. The xylem must not be crushed, so the plant will be cut at an angle with a sharp blade. The plant will be cut underwater to prevent any air bubbles getting into the xyle m, as this may affect the final results.2. I will submerge the capillary tube in the same water bowl. It will be attached to the plant, making sure no air bubbles are inside. I must make sure the open end of the capillary tube is also underwater so that all of the apparatus can be lifted out.3. This will make sure that the whole system is completely airtight. When the plant transpires, water will be pulled along the tubing. I will allow the apparatus to equilibrate for about 5 minutes.4. I am going to introduce an air bubble into the system. Holding the tubing out of the water for a minute can do this.5. I will make sure the bubble starts at the correct place on the scale, and time how long it takes for the bubble to move 50mm. This can be achieved by allowing the bubble to pass from no.1 to no.5 on the scale. Afterwards I will move the bubble back with the water.6. I will note the times in the table.7. I am going to repeat each attempt three times. This should give me enough readin gs to be able to calculate the mean average if need be. Each measurement will be taken from the same point of the bubble.Figure 3 shows how I am going to make sure the bubble is at the correct place on the scale. The bubble can be moved backwards by opening the tap from the reservoir and allowing more water in.8. Ten leaves will be removed and the surface area of the leaves calculated. The test will be repeated again. Each time I will remove ten leaves, and the last test I conduct will have only ten leaves on the plant.9. I will be conducting a practice experiment, with just one reading for each set of leaves that I remove. This will appear in my results as 1st attempt.10. Three other readings will be taken with another branch of the same privet plant. It is the surface area of this second branch that I will record. The surface area will be used to compare how the rate of uptake will change against the number of leaves I will be removing.Safety Procedures:* I will not be using any h azardous substances, but I must be careful not to spill any water on the workbench.* The sharp blade must be used with care, as it is very sharp and fingers can be cut easily. When they are not being used, the blades must be kept inside their box so that other people will not hurt themselves if they are left lying around.* I will not break any branches off the privet hedge that I will not be using for the experiment. This means that I will not be disturbing any organisms unnecessarily that live on the plant.* The apparatus must be positioned steadily on the surface. It is quite bulky, and I must be careful not to knock it over and spill the water.Predictions:I predict that if the surface area of the plants leaves is reduced the rate of uptake will slow down. This is because the number of stomata will be reduced, and transpiration rates will be reduced. I predict that the rate will decrease in proportion to the number of leaves removed, for example if the number of leaves is reduced by 50%, the rate of uptake will be reduced by 50%. The rate of transpiration is directly proportional to the surface area of the leaves on the plant. This is assuming that all other variables will remain constant. I am assuming that there will be an equal distribution of stomata on all of the leaves, and also that the surface area of each set of 10 leaves I remove will be approximately the same. For example, each set may have a combined surface area of 50 cm?.See Figure 4 that shows how I predict the rate of uptake will change. As I am unsure of the rate at present, I have left the axis unlabelled and shown only the general trend.Method:This was carried out as stated earlier, with no changes made to the original plan. The first attempt was carried out on a different branch to the other three attempts. This was to test the experiment, and it also gave me an approximate time of the whole experiment.Results:Time of Water Uptake (seconds)Number of Leaves1st Attempt2nd Attempt3rd Attempt 4th Attempt1003623753673849042342743448580409423423409703754634234716045848548049750505561543609404046945746843040978160970420704892704735101612962862943I choose to display the rate of water uptake (mm/second) rather than the time taken to travel 50mm as this gave a more accurate indication of how quickly the bubble travelled:50mm = Rate in mm/secondTime taken (s)Rate of Water Uptake (mm/second)Number of Leaves1st Attempt2nd Attempt3rd Attempt4th Attempt1000.1380.1330.1360.130900.1180.1170.1150.103800.1220.1180.1180.122700.1330.1070.1180.106600.1090.1030.1040.101500.0990.0890.0920.082400.1240.0720.0870.073300.1220.0640.0820.071200.0710.0560.0710.068100.0310.0520.0580.053I have plotted the results graph in a conventional way, with the number of leaves starting at 10 and leading up to 100. Although I carried out the experiment from 100 downwards, it seemed logical to plot the results the other way around. This shows the pattern clearly. I did carry out an experiment for 0 leaves, but the rate was too slow, and it is for this reason that I have not displayed the results I found.Figure 5 shows the results. The rates are shown, as these are easily comparable numbers to work with. They give a more accurate view of how quickly the bubble travelled over 50mm.It is clear from the graph that there is an increase in the time taken as the number of leaves decreases. The rate slows down, and the bubble travels more slowly. This is due to the decreasing rate of transpiration. As the number of leaves decreases, the numbers of stomata decrease and the rate of transpiration slows down. As the transpiration rate slows down, the rate of uptake is slowed down to prevent further water loss.Conclusion:My results show that the rate of uptake slowed down as more leaves were removed, and as the surface area of the plant decreased.The first attempt proved very useful, as I did not anticipate that the air-conditioning unit would affect my results as much as it did. The graph that I drew with the rates of water uptake shows clearly all four attempts. From this, I can see that the mean average rate for 100 leaves was 0.134mm/second. The mean average rate for 10 leaves was 0.049mm/second.This experiment has matched my predictions, however not quite as well as I had hoped. I had predicted that when the leaf surface area was reduced by 50%, the rate of water uptake would decrease by 50%. This was not the case. The mean rate of transpiration for 50 leaves is not 50% of the mean average for 100 leaves; it is nearer to 67%. The mean rate of water uptake for 50 leaves was 0.091mm/second.The anomalies from the first attempt have been marked as A, B and C. A and B have higher rates of water uptake than expected. This was because the air conditioning unit came on and moved the air around the leaves more quickly, thus causing the plant to transpire more quickly. C also has a higher rate of water uptake than expected due to the light intensity changing. The first attempt was co nducted in front of a window, and when the Sun came out the light intensity increased. The other three attempts were not conducted directly in front of a window. The time taken to transpire increases as the leaf surface area decreases. This is due to the removal of stomatal pores that allow the plant to exchange gases and water vapour. To prevent dehydration, the pores close to prevent further water loss and the rate of transpiration slows down.There was only one other anomaly throughout the whole experiment. This has been marked on the results graph as D, and occurred on the fourth attempt for 90 leaves. Although I had moved the apparatus away from the air-conditioning unit previously, on this occasion the breeze still affected my results. It did not disturb the air surrounding the leaf, as it did previously. This would have increased the rate of uptake. The cooler air meant that transpiration slowed down, having a direct effect on the rate of water uptake.The rate of transpiration was fastest for all four attempts when there were all 100 leaves on the plant, and slowest when there were only 10 leaves on the plant. All of the conditions were kept constant; therefore it was the stomatal quantity that affected the rate of transpiration.It was important that I measured the rate of uptake and not the rate of transpiration. Transpiration is very difficult to measure. The volume of water taken up is far greater than the volume of water given out through transpiration. This is because a large volume of water is used by the plant for turgidity, photosynthesis and other biological functions such as hydrolytic processes.My results shown in Figure 5 are almost linear. This matches my predicted graph, and is due to the proportion of leaves removed at each time. Although I did not realise at the time, I was removing approximately 10% of the leaves each time. This was purely coincidental, and was only discovered when I plotted the surface area against the number of leaves in Figure 6. The trend shown in Figure 5 is mirrored in Figure 6. This pattern may also have followed my predictions for another reason. The stomatal distribution across the leaf surface area may have been equal across all 100 leaves. If this was true, the total number of stomatal pores would have decreased in proportion to the number of leaves too.Evaluation:The first attempt was affected by the air-conditioning and light intensity. However, this was my practise experiment and I decided to then use another branch, approximately the same size for the next three attempts. All of the surface area calculations shown in Figure 6 are for the second branch. I made sure that the air-conditioning would not start during the second experiment, and also that I did not set up the apparatus next to another window. When the Sun shone through the window, it was very bright and the light intensity increased. I did not realise that these two factors could affect the rate of transpiration as much as they did.I did not take into account the stomatal distribution in either of my two experiments. This would have been an interesting variable to look at, however I found that I was short on time. I would have liked to have looked at the lower epidermis underneath a microscope, and made an approximate stomatal count. I could have seen if they were evenly spread, and if not, still made an estimated rate of uptake from my other results.My results were very pleasing overall. They followed my predicted trend and I have been able to see why, due to measuring the total surface area of the second branch. I have accounted for my anomalies as the experiment was affected by factors beyond my control. I had not realised that the air-conditioning and positioning of the apparatus would affect the experiment in such an extreme fashion. Factors such as light intensity and the temperature of the surrounding air may only change slightly, but have a larger effect on the overall experiment.I would have liked to repeat the experiment again, so that I could obtain more results. This would give me a more significant mean average, and I would have been able to leave out the anomalies in the analysis. A source of error may have been counting the number of leaves rather than the surface area. Nevertheless, it turned out that I was removing the leaves by nearly 10% each time.I would improve the experiment by measuring the stomatal distribution next time. This will allow me to calculate a more significant rate of uptake by calculating how much water is taken in through each stomatal pore. I could then estimate how much water should be taken in. If I was able to calculate the transpiration rate as well, I would be able to work out how much water was being used within the plant.Generally, this experiment was conducted well. The anomalies were not large enough to change the trend in any way, and the overall results were beneficial in proving the hypothesis correct.

Montana 1948 Practice Essay Essays

Montana 1948 Practice Essay Essays Montana 1948 Practice Essay Paper Montana 1948 Practice Essay Paper Maturity may come at any age any time in a persons life. One moment he or she may be a carefree child, and then suddenly realize that they have been transformed into a mature adult by a powerful and traumatic experience, which they will remember their whole lives. After that, they were never same again. As a result, they rapidly matured into adults. In Montana, the summer of 1948 held a series of tragic events which were to have a permanent and decisive impact on David and his parents. This chain of events were turn David’s young life and his family upside down forever which was to so quickly lead him out of childhood, destroying his innocence and youthful naivety in the process. However, David’s shocking revelations lead to his painful gaining of wisdom. Firstly, David started to change his mind since their housekeeper, Marie Little Soldier’s illness. She refused to see the doctor Frank which is brother of David’s father Wes. Wes called Frank come to house, but Marie insisted Gail stay in room together. After Frank went, she told Gail horrible things that Frank has been doing to Indian girls in reservation. David overheard the conversation between Gail and Wes. â€Å"†¦I was beginning already to think of Uncle Frank as a criminal†¦Charming, affable Uncle Frank was gone for good. †P49 David thought his uncle was good until he heard those frightening statement. David knew this information would change him forever. He took one step toward adulthood by hearing and understanding what his uncle has done. Unfortunately, Marie dead after a few days Frank went to the house. Frank claimed her dead because of pneumonia. Basically, she was sick, but David knew better, he went to deputy sheriff Len McAuley’s house. Len was drunk and reveals the fact that he also saw Frank walking into house before Marie was found dead. David chose to tell his parents what he knew, or at least part he knew about Frank. This shows that he was developing in the area of honesty. Before, David would kept all this to himself, rather than face his parents with knowledge he knows will displease them. Furthermore, a loss of David’s innocence also appears during his killing of a live magpie. This brought an evil in him also reinforcing the fact that he has killed a living creature in the wild and mentioning that â€Å"it can be done in a flick of the finger† â€Å"†¦Looking in the dead bird’s eye, I realized that these strange, unthought-of connections – sex and death, lust and violence, desire and degradation – are there, there, deep in even a good heart’s chambers. †P82 Finally, Wes chose to arrest his brother. Instead f taking him to an actual jail, he thought that he can reduce his murderer and rapist brother some embarrassment by locking him in basement. Julian Hayden sent some men from ranch came to house to break Frank free. Here David was close to being an adult because he realized how he must act and the gravity of situation in which he and his family are involved. He’s far from the child who once looked forward to visits from his uncle and visits to grandfathers ranch. As an adult, he is concerned with the welfare of his family and parents well-being emotionally. David would like to stand by his family when they are in need. He didn’t desert them or feel shameful. He stayed loyal and true to those he cares for and loves. Thus, he has shown his ability to act as an adult should. As a result, in the rapid journey which David has been forced to undertake from innocence to experience, to seeing life in a whole, truthful and certainly more painful way, he learns many lessons and gains important insights, but none more disturbing than that which immediately follows Frank’s suicide. â€Å"You see, I knew! I knew! – I knew! That Uncle Frank’s suicide had solved all of our problems †¦ I felt something for my uncle in death that I hadn’t felt for him in life. It was gratitude, yes, but it was something more. It was very close to love†. P161-162 One can never be too sure when the innocence of childhood is lost, the sure thing is that everyone becomes an adult eventually, and thats when they lose their innoc ence. In many cases, this change from child to adult is a harsh thing, and often it is the realization that the world is not perfect.

Contemporary issues in marketing Essay Example | Topics and Well Written Essays - 4000 words

Contemporary issues in marketing - Essay Example All the above phases mean that the strategy to be developed should effectively put the principles of the company closer to the needs of the specific consumers that the company targets. If a company puts the above in consideration then it will definitely develop unique strategies that make it competitive in the new market. This is addition to proper review and correction policies will determine the success of the adapted international marketing mix that Weny Trippes (fictional company) has developed. Weny Trippes has a really wide market appeal in the soft drink market in the United States. A company such as Weny Trippes has the ability to introduce new products that meet the demands and quality requirements of its consumers faster than any other company in the local scene. It has better consumer need responsiveness, better innovative skills, quality products and processes as well as higher efficiency that promotes its differentiation advantage in the United States market. This has ma de the company to consider developing marketing strategies that can ensure the success of its product line in other foreign markets such as those of Central America, East Africa, or Northern Europe, Chinese market and the Middle East markets. Different foreign markets have different needs and present unique different challenges that Weny Trippes has to form effective entry and marketing strategies on how to overcome them. ... Increasing competitiveness on a global ground has forced many industries to expand to foreign countries. Internationalisation, which is the process by virtue of which a firm moves from operating in its domestic market to international markets, has hence become an ongoing trend in the economy. But this however may have effects that are not evident in the domestic sector especially in terms of coping up with a foreign environment. The international market for many products is subject to many dynamic influences that can lead to changes in the volume, mix and distribution of demand and sources of competitiveness (Ofori 2000). Before this decision to venture into the market Weny Trippes only ventured the domestic market and never thought of expanding its business beyond the borders of its home country. The international penetration option for the companies is a means of expanding the profits and at the same time attempting to cash on the weakness and lack of creativity by the home compani es or firms that produce similar products (Akkaya 2006). Organizations are optimally entering into newer foreign markets mainly the onset of globalisation. â€Å"Globalisation is a process of interaction and integration among the people, companies, and governments of different nations, a process driven by international trade and investment †¦. This process has effects on the environment, on culture, on political systems...† (Rothenberg 2002, p1). Thus, its wish to make an impression in foreign markets is further driven by the globalization. In addition, Weny Trippes has a really diverse range of soft drink products and energy drinks that it intends to develop an international marketing strategy so as to promote them in several foreign markets.