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Question: How do Diatoms react to variable amounts of light?
Hypothesis: The Diatoms will reproduce best in the natural light. This is simply stating our common knowledge, per example we still do not know how well they would do in all light for 24 hours and we do know that without light, plants can not grow well.
Experiment: We will have 8 flasks, each containing Diatoms: Ondontella Longicruris. 2 of these flasks will be under a light for 24 hours for a period of ten days. 2 more will be blocked out from any light source possible for 24 hours for a period of ten days. 3 others were put beside a window to receive natural light. The last one will be kept under laboratory conditions as our control, there for receiving 14 hours light and 10 hours dark.
Materials:
8 flasks/containers
Diatoms --> Ondontella Longicruris
Light source
Method of controlling temperatureFor counting:
A Spectrometre20D
Procedure:
Temperature Records
Light for 24 hours
|
Day |
˚C of the morning 8:15 |
˚C of the evening 5:00 |
|
1 tues 6/07 |
|
15.4˚C |
|
2 wens 7th |
15.3˚C |
15.5˚C |
|
3 thurs 8th |
15.4˚C |
15.9˚C |
|
4 fri 9th |
15.5˚C |
15.7˚C |
|
5 sat 10th |
15.8˚C |
16.3˚C |
|
6 sun 11th |
15.9˚C |
15.8˚C |
|
7 mon 12th |
15.5˚C |
15.6˚C |
|
8 tues 13th |
15.4˚C |
14.8˚C |
|
9 wens14th |
14.9˚C |
14.3˚C |
|
10 thurs 15th |
15.3˚C |
15.2˚C |
|
11 fri 16th |
15.5˚C |
|
No light for 24 hours
|
Day |
˚C of the morning |
˚C of the evening |
|
1 tues 6/07 |
|
14.9˚C |
|
2 wens 7th |
14.7˚C |
14.4˚C |
|
3 thurs 8th |
14.9 |
15˚C |
|
4 fri 9 th |
15.1˚C |
15.3˚C |
|
5 sat 10 th |
15˚C |
15.1˚C |
|
6 sun 11 th |
14.4˚C |
15.9˚C |
|
7 mon 12 th |
14.3˚C |
14.7˚C |
|
8 tues 13 th |
14.5˚C |
14.4˚C |
|
9 wens14 th |
14.7˚C |
14.8˚C |
|
10 thurs15 th |
14.6˚C |
14.6˚C |
|
11 fri16 th |
15.6 |
|
Natural light
|
Day |
˚C of the morning |
˚C of the evening |
|
1 tues 6/07 |
|
15.4˚C |
|
2 wens 7th |
15.9˚C |
16˚C |
|
3 thurs 8th |
15.9˚C |
15˚C |
|
4 fri 9 th |
14.9˚C |
15˚C |
|
5 sat 10 th |
15.9˚C |
16˚C |
|
6 sun 11 th |
14.9˚C |
14.8˚C |
|
7 mon 12 th |
14.8˚C |
14.7˚C |
|
8 tues 13 th |
14.8˚C |
14.5˚C |
|
9 wens14 th |
14.3˚C |
14.4˚C |
|
10 thurs15 th |
14.3˚C |
14.5˚C |
|
11 fri16 th |
14.4˚C |
|
Spectrometer 20D
This machine measures absorption and reflection of light. The chlorophyll in the water absorbs the red light and reflects out in return the green light, and therefore the machine measures the absorption. The next step would be to use a special equation to calculate the number of phytoplankton (diatoms) per tube. The color is related to the number of diatoms because of the chlorophyll that they produce.
Results
Our experiment helped us to discover that phytoplankton need to rest. At the beginning of our experiment we thought that with more light the diatoms would be all hyper active and reproducing like crazy. Although our hypothesis was that the natural light would do the best. Our reasons for this was stating our common knowledge, for example, we did not know for sure how well all dark or all light would do, so we concluded that the natural light would do the best. On the contrary, at home the all light did do the best; however the control that was kept in laboratory conditions was definitely top. This can be seen in our graph below this paragraph. We did have problems while conducting this experiment; the temperatures were not exact. The average temperature that all phytoplankton need is 16˚C minimum, if you look at our temperature records it is apparent that they only had 1 to 3 times in each section where they reached16˚C. Next time we would like to control the temperature.