Mackenzie Singer

Lab 12

11/8/18

Objective:

The purpose of this lab was to gain an understanding of evolution and the thought that all organisms branch off a common ancestor. We also used the soil previously collected to observe the ciliates within it and started a soil texture test that will be observed next lab.

Procedure:

Soil texture:

1. Remove sticks and other debris from the soil sample.
2. Add soil to about the 4ml mark in a Falcon tube.
3. Add water to the 10ml mark and mix vigorously.
4. Add 1 drop of dispersing agent and re-mix.
5. Observe the tube after 30 seconds.
6. Place the tubes in a rack to sit for a week.

Observation of ciliates from non-flooded plate:

1. Use a micropipette to transfer 100µl of the water in the non-flooded plate to a clean concave slide.
2. Observe the drop under the compound microscope.
3. If ciliates are found but soil makes it hard to see them, take five 5µl drops of water and place on a clean slide.
4. Transfer 5µl of the water from the 100µl drop and place it in one of the five drops.
5. Dilute the solution along all 5 drops and observe.

Observations:

I found ciliates, but they were much easier to see after diluting across the 5 drops. I was unable to take a picture because they were very small and moved too fast. They were small, circular, and clear.

Storage:

The microscopes were covered and put away. The Falcon tubes were placed in a rack to be stored for a week. The soil bags were placed in a bin and put away. The soil petri dishes were placed under the fume hood.

Conclusion and Future Steps:

Evolution is a very important concept to understand because it reveals how all forms of life are connected to one another. This helps a lot with experiments so that a close ancestor or closely related organism can be observed to find results for other ones similar to it. A lot of organisms are more closely related than I had thought, which was very interesting. Future steps will be to observe the soil texture samples in the Falcon tubes and observe more ciliates.