MOD007175 CORE BIOLOGY 2020-21
PRACTICAL LABORATORY REPORT
The lab report is on osmosis in the potato using maltose under different conditions. See all the material and videos on the trimester 2 week 5 canvas site.
There is a MAXIMUM word count of 1000 words (1000 is the absolute word limit). The report must follow the guidelines below. The report is worth 20% of the module mark for MOD007175. The report is marked out of 100 and the marks for each part of the report are indicated on the template.
When writing the report it must be in your own words – be careful as there are a lot of essays on this topic on the internet and if you can find them so can Turnitin and me – therefore make sure you put through the check originality report (COR) on Turnitin before submitting to the Turnitin site.
The lab report should follow the instructions and template given below. The report must be fully referenced using Harvard style of referencing https://library.aru.ac.uk/referencing/harvard.htm and there should be reference for the method as well as extensive referencing for the introduction and discussion.
For the experiment you will be sent two sets of data the first set will be different concentrations of maltose and the mass of the potato strip pre (initial weight)- and post (final weight) -incubation in the maltose. You will need to decide (a) the length of incubation time; (b) the size of the potato strip; (c) the temperature at which you are carrying out the experiment; (d) volume of maltose used. The second set will be the same concentrations of maltose but in the second experiment you need to have the potato strip twice the length and width of the size in the first experiment, so that whatever dimensions you put for (b) then double these for experiment 2. All other factors must be the same as in experiment 1.
To work out the results for each concentration you need for each individual test to subtract the pre-weight from the post weight and then work out the % change (((final wt-pre wt)/pre wt) x100) for each single result, then determine the mean (average) for tests 1-3 for each concentration. Do the same for experiment 1 and experiment 2 to give 2 sets of data. Then plot a graph of mean % change in weight on the y-axis and concentration of maltose on the x-axis, putting both lines on the same graph, giving the mean and add the error bar using the standard deviation calculated for each point. There is a video on calculating the results and plotting the graph on week 4 on-line canvas page. You should watch the videos on the week 5 practical page to help with writing up the experiment.
Title: (3 marks)
Descriptive title that indicates to the reader the subject of the report
Introduction: (15 marks)
Background to subject
Introducing key terminology
Aim of the experiment and the hypothesis (or null hypothesis rather than the hypothesis)
Method: (7 marks)
Very briefly outline the method but it must be written in sentences in the past tense.
Give sufficient information to be able to repeat the experiment but not info that usual science practice.
Therefore, need to give information such as concentrations, volumes used, timings, size of potato strip, temperature of incubation
but NO list of materials or equipment and not detail of routine equipment, such as test tubes, pipettes
not step by step instructions, write in sentences and paragraphs. No bullet points
Results: (30 marks)
Data will be provided for different concentrations of maltose and you define the other parameters in the method.
To include:
Table of results that is mean and SD only (not individual numbers for each tube)
Graph of change in % change in weight (plot the mean and error bar using the standard deviation of the potato on the y-axis against maltose concentration on x-axis. Plot two lines on the same graph, so give a key to indicate which is the smaller and which the larger potato strip. Also add for each line the R2 number, find this in excel – add trendline and under trendline look for more options and at bottom at R2 as this will indicate if there is a good correlation between the concentration of maltose and the %change in weight . Then in discussion use this value to comment on whether or not a correlation between the changes and the findings.
Text: short summary of the key findings- NOT what happens for each tube but the general trend of the results and the correlation coefficient.
Discussion: (20 marks)
What do your results mean? Discuss in terms concentration of maltose related to hypo- hyper- and iso- tonic to the cell contents and water movement (osmosis) and how the cell will change. What does this show in terms of what is happening inside the cell of the potato? How do these change dependent on the size of the potato strip and explain the difference? Would the results be different if animal cells and not plant cells were used?
Give the limitations of your study.
What would be the next experiment to do?
Reference list: (15 marks)
in Harvard format, using a range of good quality sources (minimum 10 references) (20 marks)
Presentation: (10 marks)
is the overall report correctly formatted, are the figures and tables correctly formatted, are there no spelling mistakes and is the report grammatically correct?
The report should be uploaded to Turnitin before by 2pm on the date on your e-vision record