Aim
⇨What are you trying to investigate?
I am trying to investigate how water affects the growth of bacteria.
Prediction & Hypothesis
⇨What do you think the result will be?
⇨Explain why you think this?
⇨Use scientific ideas and words.
⇨Include chemical formulae, diagrams and sketch graphs if you can.
I think the bread with 8 ml of water will have more bacteria growing on it. I believe that bacteria could not grow well, or not at all, without water. Therefore I predict that both of the dry petri dishes will have very little bacteria growing inside them. I think that the more water in the bread, the more bacteria growing. Hence, the 8ml Petri dish would have more ...view middle of the document...
) Place the lid on the Petri dish
6.) Stick a piece of sticky tape around the bottom and top of the Petri dish, securely closing it.
Fair testing
⇨Which variable will you change?
⇨Name the three most important things you must keep the same?
⇨No marks for simply saying ’keep everything the same’.
I will change the amount of water in each petri dish. One of the dry petri dishes will be open.
The size of the size of the petri dish, and the amount of the bread was exposed to bacteria must always be the same.
Diagram
⇨A simple, pencil and ruler diagram of how you will set up the apparatus.
Observing
Table
⇨Draw up a clearly labeled table with units in the headings.
⇨Use the same number of s.f./ d.p. throughout.
⇨In biology, we never need to use more than three sf, two is often enough.
⇨Make sure that you show results from at least three repeats of the experiment.
⇨Your table should also show the average result for each treatment.
Treatment of bread Amount of dots counted
1 2 3 4 Mean
Dry opened 1 0 0 0 0.25
Dry closed 0 8 2 14 6
4ml of water 37 32 33 8 27.5
8ml of water 49 42 65 68 56
Observations
⇨Mention anything which went wrong or seemed odd when you were doing your practical.
⇨Describe any changes you can see, but did not measure.
Analysing
Charts
⇨Draw a simple, clear bar char or graph, as appropriate, to display your results.
⇨It should show just the averages from your table.
⇨You can draw this by hand, but it must be on graph paper and stuck in or attached.
⇨Use Excel only if you can use it to draw and scale a perfect chart.
⇨It should be at least...