The object of the experiment is to see how maggots respond to certain stimuli such as light.

Firstly draw a circle in the middle of a paper towel, this is so the maggot can run the same distance in any direction, and then wet it universally. The circle should be the size of a ten pence piece and the maggot should be dropped inside.

The paper towel should look like this:

The maggot should be placed in a test tube for five minutes then put into the environment so it can accumulate to the water bath temperature. After five minutes take the maggot out and place it on the paper and start the clock for thirty seconds. After thirty seconds, stop the clock and measure how far the maggot travelled. It is impossible to measure the maggot's steps entirely so measure from the start to end in a straight line. These results will be valid as the maggots are all the same and the experiment discusses the responses of maggots.

In the preliminary experiment many things were seen. It is quite difficult to drop the maggot into the circle so extra care has to be taken. More than five temperatures should be taken which are: 50°C 45°C 40°C 35°C 30°C 20°C 15°C 10°C 0°C. After the results have been taken repeat them twice more then take an average. All the results were valid such as when the maggot was at 0°C the maggot did not move at all because it needed to retain body heat. After it had been placed at 40°C the maggot ran around very quickly and moved quite far, almost off the paper. The measurement as the crow flies was 25 cm.

Also when put in at 50C the maggot died as the heat was too much for it. Therefore in the proper experiment the maggots should not be put in extreme conditions and the distance should be measured as the crow flies so as to keep everything the same.

Results from preliminary work:

0°C 0cm

50°C 0cm

35°C 31cm

21°C 15cm. There was not enough time to repeat and check.

The maggot's central nervous system should not react as quickly at fifty degrees Celsius and zero degrees Celsius. It has enzymes so at 50°C they should be denatured and at zero they should be too cold to function properly.

Factors which must be kept constant: Light intensity

Amount of water on tissue

Place of measurement

The only things that should change are the speed and temperature of the maggot.

At the end the speed should rely on the temperature of the maggot.

Obtaining Evidence

The method in the plan was used in the experiment; however, some things were changed. The whole room had to be darkened for other experiments, therefore to keep constant light a lamp had to be put over the paper. This had the side effect of heating the paper and evaporating some of the water. This meant that the paper was not universally wet. This made the experiment unfair as it introduced another variable into the experiment. However, I do not think that it affected the results at all. The temperature in the room was kept constant so as not to introduce a variable. This helps to make the experiment fair. Unfortunately some of the time the maggots died as the temperatures were too extreme. The maggots were all fine, some were dyed but some were not. The dye did not affect any of the maggot's movements or resistance to heat. All the maggots were put in the same flasks and test tubes for the same amount of time. There were no dangerous chemicals or equipment being used, so there was no need to wear protective equipment. The only need was to wash hands after handling maggots as they are not clean creatures.

There were water baths at many different temperatures: 40, 50, 30 and 0 degrees Celsius. Each one produced a different answer. Room temperature was also used and was 22°C at that time.

Each maggot was put into its environment for five minutes and then put directly onto the paper. Then they were timed for thirty seconds and measured as the crow flies because it was too hard to do it any other way.

A table of results:

Temperature maggot was put in

(°C)

Distance travelled

(cm)

0

5.0

0.1

0.0

22

21.0

21.2

9.6

30

25.3

23.7

27.8

40

7.2

8.9

20.4

50

0(dead)

0(dead)

0(dead)

There seemed to be no way that the maggots would stay alive at fifty degrees for five minutes as the temperature was too great. Class data could have been used but people were attempting different responses. The results are not very anomalous but class data would have smoothed out any anomalies that people might have had.

Analysing Evidence

From the evidence from the graph as well as the table, the maggots responded to many changes to their environment. These results agree entirely with my hypothesis and this was therefore a successful experiment. The graph is shaped as an upside down parabola because at a certain temperature the maggots died and so the line could not continue. The evidence is not completely clear because the measurements were made "as the crow flies" the distance was probably slightly more because on a few occasions the maggot moved forward and then turned accounting for more distance travelled. There should not be a line of best fit because the evidence was with temperatures so after 30°C the movement slowed down as there was a bigger change from the environment it was put in to the room temperature. The results support the conclusion because the rate of movement decreased as the environments became more extreme.

Evaluation

The procedure worked fine but improvements could have been made. There were one or two slight anomalies but as we did not use class data the results were not ironed out in an average. This was because different people were performing different experiments. The results could have been collected more accurately because we measured the distance from the start of the maggot to the end in a straight line and this did not allow any results for when the maggot started and then changed direction half way. More maggots could have been used to give more accurate readings but there was not enough time.

The measurements could have been more accurate if the ruler's increment had been more detailed. If more people had done the experiment I had done then averages could have been taken and so the anomalies could have been ironed out. If the experiment had taken place in a room with equal lighting and material on the tables it would have been more accurate as other people were performing experiments with light so some of the maggots could have been reacting to this and so they moved faster. The evidence was quite reliable and it supports the conclusion as the results are very proportional and what should be suspected, even if there were a few anomalies.

Overall the experiment was a success and the results were quite accurate except for a couple of anomalies. The hypothesis tied up nicely with the conclusion and so the experiment was a success.

Ronald Lin H 28/04/2007 2Bt/NJT