Recently we had to conduct an experiment on Osmosis in potato chips by looking at the effect of sucrose concentration.
We weren't taught very well, and I'm a complete dunce in Biology,so my coursework/understanding of all this is fairly limited.
However, I got reasonable marks,except my evaluation only recieved 3 marks out of a possible 8.
My coursework got a B,but is only 3 marks away from an A-improving it would get my predicted grade up to an A as coursework is worth 33%(ish) -so I really need this.
My teacher can't help me or tell me how to improve my grade and gain more marks, so I'd love some help and advice since I can't even remember what the rubbsih i wrote is supposed to mean!
Would love any help you can give me, the evaulation is below,tell me if you need more info.
I think the Experiment went well as our results were precise, and we had small error bars. The lack of outliers in the experiment also showed that the results were precise, although not necessarily reliable. I think we took enough results for the amount of concentrations we were using, and that the 24 hour period of incubation was enough time for sufficient Osmosis to occur.
Although our results were precise, We could have improved our experiment. Cutting the Potato chips by hand could have created flaws in our results due to the possibility of human error. By using a mm ruler and a scalpel, the measurements for cutting each chip could have been inaccurately applied. A more precise way of measuring the length of chips could have been by using some sort of machine, or cutting it to the specific size by having a metal outline prepared. We could have found a more accurate way to measure the solutions and determine concentrations. Using a burette could have ensured that we had an accurate amount of test fluid in each tube. I could have found a more accurate scale to weigh each chip, as to get a more precise result , or weighed it on two different scales to make sure there was no error. Also, the paper towels used to dry the chips could have created an error in mass, and therefore we could have dried for longer to increase accuracy as there would be less moisture.
These problems could have affected the reliability of our results as there could have been errors in the measurements, and therefore errors in the results and calculations. My suggestions would help overcome these problems as they would make my results more accurate and therefore more reliable.
To make plotting the line of best fit more accurate, maybe we could have recorded our results to a closer decimal place so that the results are more precise and the line of best fit can be plotted more accurately. I could have also made my graph more accurate by taking up more space and making the markers for each point in sets of one, rather than in sets of 2. This would have allowed the line of best fit to be easier to read, as it would be more broadly spaced out. I could have considered leaving points out which created slightly larger error bars and therefore made the points less accurate, and the line of best fit less reliable.
To pinpoint the Isotonic point more accurately we could have repeated the experiments within a narrower range around the Isotonic point which we worked out. This would give us a more accurate idea of where the Isotonic point is exactly.
To Investigate Osmosis more accurately I could have used something other than a paper towel to dry the chips from moisture. However, the preliminary experiments showed that filter paper is even more unreliable, so I can at least conclude that although I needed to dry the Chips longer, I used a fairly suitable source from those available to me. Overall, I think the Investigation was fairly successful as my results all follow a pattern and appear fairly reliable.
OCR 21st Century GCSE Biology Coursework-Evaluaton help!? watch
- Thread Starter
- 08-02-2010 20:19