Few Large Bubbles At 10 Cm example essay topic

Biology Investigation Problem: How does light affect the rate of Photosynthesis? The Plan In my experiment I am going to see how light affects the rate of photosynthesis. To do this experiment I am going to set up the apparatus as shown in figure 1. The apparatus I am going to use are the following: -1 Tripod 1 300 ml Beaker 1 Boiling Tube 1 Clamp Stand 1 Clamp 1 Boss 1 Ring Binder 1 Lamp 1 1 Metre Ruler 1 Thermometer 1 Stop Clock To do the experiment I will set up the apparatus first. I will firstly place the tripod on top of the base of the clamp stand and fill the 300 ml beaker with 250 ml of water to create the water bath. I will place the boss in the middle of the bar on the clamp stand and place the clamp in the boss.

I would then fill the boiling tube 43 ml of water, put the pondweed in it and place it in the clamp. I would place the ring binder around the clamp stand surrounding the water base. Finally, I would plug in the lamp and place it 10 cm away from the pondweed. I done a preliminary experiment to get an idea how to do the main and proper experiment and what would happen in the experiment. In the preliminary experiment we didn't use the safeguards so it wasn't fair experiment. We did this because it gave us the idea what problems we might face when we did the main experiment and gave us the idea how to do it.

The pondweed should create photosynthesis by the following equation: -6 CO 2 + 6 H 2 O 6 C 6 H 12 O 6+ 6 O 2 Photosynthesis occurs when plants take in Carbon Dioxide from the surrounding air in its leaves and water from the nearby soil in its roots. The leaves then take light energy from the Sun, which is absorbed in the chlorophyll in the cells and passes it along for it to be used in photosynthesis. Glucose is produced and is converted into Starch to be stored. Oxygen is produced from the water and it is a waste product so it is released into the air.

The plant uses Carbon Dioxide and water to create Carbohydrates. Glucose is a small, soluble molecule which is useless for a plant to use as energy but it converts it into Starch, which is a large and insoluble molecule, so it can be stored for to be converted back into Glucose. I made this experiment as fair as possible. Firstly, I put Sodium Bicarbonate in the boiling tube to enrich the water with Carbon Dioxide so more Oxygen bubbles would be produced. I had kept the volume of the water in the 300 ml beaker and in the boiling tube the same so the temperature could stay the same, as that would affect the rate of photosynthesis. I put a ring binder around the clamp stand so that 'foreign' light wouldn't be collected by the pondweed and continue photosynthesis after I had switched of the lamp.

I constantly checked the temperature of the boiling tube and the beaker so it wouldn't affect the rate of photosynthesis. I used a thermometer to check the temperature and I used a water bath to regulate the temperature of the boiling tube. I continuously used the same pondweed in all of my experiments so that the amount of chlorophyll would stay the same and the amount of Oxygen produced would also stay the same. I predict that the amount of oxygen produced by the pondweed should decrease as I increase the distance between the boiling tube and the lamp.

The rate of photosynthesis should decrease as I decrease light intensity and it should increase as I increase the light intensity. Obtaining Evidence Distance Preliminary Attempt 10 cm 7220 cm 5430 cm 2340 cm 1850 cm 22 This set of results is the preliminary attempt. The results are inaccurate because it wasn't a fair test, as I didn't use any safeguards. 22 has a star next to it because it is an anomaly. This is due to the fact that no safeguards were used and possibly the pondweed caught 'foreign' light.

The anomaly in these results is 65 because not all of the Sodium Bicarbonate was mixed in the boiling tube with the water. Attempts Distance 3 4 Average 10 cm 70 64 6720 cm 56 52 5430 cm 29 28 28.540 cm 15 15 1550 cm 8 7 7.5 These are the second set of results done with fair testing. There are no anomalies in these results because all the safeguards were down properly. I have tried to make my readings as clear and accurate as I could have possibly. I had made sure it was a fair test by adding Sodium Bicarbonate in the boiling tube to enrich the water with Carbon Dioxide so more Oxygen bubbles would be produced.

I also made sure that the volumes of the water in the 300 ml beaker and in the boiling tube the same so the temperature could stay the same, as that would affect the rate of photosynthesis. I put a ring binder around the clamp stand so that it would block 'foreign' light that would be collected by the pondweed and continue photosynthesis after I had switched of the lamp. I believe my method was not really suitable because there were a few problems with it. I chose to count the bubbles which proved to be inaccurate because of the size of the bubbles and the rate which the bubbles were released. The size of the bubbles was a problem because sometimes the bubbles would be large at 10 cm and this would have had a low reading whilst I might have had small bubbles and counted a lot at 50 cm.

I believe I have made clear observations because my results show a general pattern among the readings that is very noticeable. My results can be read easily and that they are very neat. I have used a suitable range of observations and I have done the experiment four times with fair testing, which I am happy about. Even though I did say that counting bubbles was inaccurate and that it could cause a few problems, in general, my results are quite broad satisfactory for me. Analysing Evidence From readings I found that, overall, the amount of bubbles decreased as I decreased the intensity of the light.

There was a distinct pattern among my results as I could see the amount of bubbles produced decreased with the increase of distance. This shows that the pondweed received less light every time the distance increased so the amount of photosynthesis that took place decreased. My graphs should make my readings clearer and give a general picture about the amount of photosynthesis produced against the distance. My graph should also show common results among my averages.

My results basically show the bubbles decreasing with distances increasing. This is because the amount of light stored by the chlorophyll is decreasing because the light intensity is getting weaker. This affects the amount of Carbon Dioxide taken in by the leaves and the amount of water taken up by the stem. As the amount of Carbon Dioxide is decreasing, the amount of Oxygen being produced as a waste product decreases along with it the amount of bubbles produced. The amount of Glucose produced would also decrease and there would be less energy for the plant to use. This is because the amount of photosynthesis produced by the pondweed reaches a certain point where it can't take in light anymore and the other materials used for photosynthesis are wasted.

This is show in the 1/d graph. The straight line is going diagonally which it shouldn't because it shows when the plant stops taking in light. My results confirm my prediction that the amount of oxygen produced by the pondweed should decrease as I increase the distance between the boiling tube and the lamp. This shows that I have made clear observations and that my results are satisfactory. My results confirm my prediction because of the fair testing I did.

My results followed my prediction except for one anomaly, which I believe happened because I didn't mix the Sodium Bicarbonate thoroughly enough with the water. Evaluating Evidence My results were fairly accurate overall but could have been more accurate. My results were fairly accurate overall but it did present a few problems like the size of the bubbles and the rate in which the bubbles were released. The size of the bubbles affected the reading because you could have a few large bubbles at 10 cm and have a small number for the reading but you could have small bubbles at 20 cm and have a larger number for the reading.

In my readings there are 3 anomalies altogether. The first one is 120 bubbles at 10 cm and this happened because they were small bubbles that were released very fast. The penultimate anomaly is 68 bubbles at 20 cm and this happened because the bubbles were smaller than the rest of the readings in the 20 cm category. The final anomaly is 22 bubbles at 50 cm and this happened because these were also small bubbles compared to the rest of the readings in the 50 cm row. I am satisfied with my experiment even though I know it was only fairly accurate overall and could be improved.

It was fairly accurate because we counted the bubbles released but it was partly inefficient because we could have missed bubbles released as the leaves themselves could have caught them. My experiment could be improved by using a micro burette to measure the volume of the Oxygen released instead of counting the bubbles released by the pondweed. The micro burette is a much better to use for the experiment because it gives us the volume of the Oxygen released from the pondweed and is much more accurate. Counting bubbles arose a few problems like inaccurate results and the total Oxygen released wasn't recorded each time because of the size of the bubbles. Counting the bubbles was also a bit inefficient because we could have missed bubbles released as the leaves themselves could have caught them.