Friday, February 19, 2010

Diatom Investigation, By Miranda.

My question:
What is the difference between the amount of diatoms at 5in. down and 20in. down?

Variable changed- Depth, 5in. and 20in.
Variable measured- The amount of diatoms.
Controls- Stay the same! By looking through the slides the same way, use the same amount of time looking through each slide (in my case 5 mins). Make each slide the same way everytime, using the same amount of dirt, water, and puting it together the same way.

1. Use a ruler to measure down 5in.
2. Get a slide ready with dirt from the 5in. mark.
3. Look throughout slide with microscope for 5 mins. in a zig-zag pattern.
4. Write data for that slide in 1st box of chart.
5. Repeat those first 4 steps twice more but write data in its own box on chart.
6. Now measure down to 20in.
7. Make another slide the same way you have been and with the same amount of dirt and water you have been except with dirt from the 20in. mark.
8. Look through slide with micrascope (using same controls)
9. Write data in own box on chart.
10. repeat those 6-9 steps 2 more times but while writing data in its own box on chart.

With the first three slides from the 5in. mark, I found 5, 11, and 8 diatoms giving me an average of 8 diatoms at 5in.
With the first three slides from the 20in. mark, I found 17, 21, and 13 diatoms giving me an average of 17 diatoms at 20in.

-There were less diatoms at 5in. than at 20in.
-At 5in. there was an average of 8 diatoms and at 20in. there was an average of 17 diatoms.
-This may be because at the 5in. layer the enviroment was more harsh and so the diatoms had a harder time living.

Further questions:
  • What are the types in a core from the shallow part of the lake versus a deep part (using 10 in. down in each)?
  • Are there more Melosiera or Syndra in 5in. down or in 20in. down?

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