User:Christian Ortiz/Notebook/Biology 210 at AU

January 25, 2015 - CO Observing a niche at AU

Introduction: The theory of evolution by natural selection is one of the most important theories in biology. To help grasp this theory it was necessary to observe evolution by examining different niches at AU. By observing the characteristics of a niche we are able to see the diversity in an environment. This ecology would help us understand the interactions between multiple organisms in a single environment. The hypothesis for this experiment is that the characteristics in this niche would be rather simple in terms that the diversity of organisms would not get more complex until the sample is under the microscope.

Material/Methods: Each group was assigned a 20 by 20 meter dimension piece of land. A ground sample was taken from the transect and placed in a sterile 50 mL conical tube. This sample would be used to make a Hay Infusion Culture. To make the Hay Infusion Culture the ground sample was placed inside of a plastic jar that contained 500 mLs of deer water. Before closing the jar and mixing gently, 0.1 grams of dried milk was added to the container. Lastly, the lid was taken off and the open jar was placed in the lab room.

Data/Observations: The transect the group received was a piece of land that that interacted with a sitting area. Its location was in the center of the Quad. From East to West, the transect had grass that lead up an area of bushes. This area of bushes was supported by soil under it but the soil also had its own area. The soil would also meet up with the cement bench. The biotic components of this transect were the bushes, soil, and grass. The abiotic components of the transect was the cement bench. This image is a sketched aerial-view of the transect with both biotic and abiotic factors.

Conclusion: Based on the fact that there was few abiotic and biotic factors it is safe to say that the hypothesis was right. From an aerial view, there was very little diversity interactions between the components. The Hay Infusion will probably make everything a lot of more complicated. To improve this experiment I would have preferred taking a picture as opposed to sketching out the landscape. This would allow for more accurate representation of how the transect looked.

January 28, 2015 - CO Algae and Protists in a Transect

Introduction: The purpose of this experiment was to examine any algae and protists in the transects. Algae and protist are part of two large groups of unicellular eukaryotes. The main difference between the two is that algae perform photosynthesis and protists consume nutrients.This project was also meant to teach students about identifying unknowns by using a dichotomous key. The key helps identify organisms based of observations about their size, shape, movement, and color. The hypothesis for this experiment is that all the algae would be near the plant or at the bottom samples.

Material/Methods: The 500 mLs of the Hay Infusion Culture was used for sampling. Using a transfer pipette two samples were taken from the container. One sample was from the top of the container and the second sample was from the bottom of the container. These samples were placed in labeled wet mounts and set under a microscope at both 10x and 40x. The last procedure called for a preparation of a serial dilution. Four 10 mLs tubes with broth were labeled 10^-2, 10^-4, 10^-6, and 10^-8. Then four nutrient agar and four nutrient agar plus tetracycline plates were both labeled 10^ -3, 10^ -5, 10^ -7, and 10^ -9. The four four plates that contained tetracycline were labeled "tet" as well to help differentiate. The original 500 mL of the Hay Infusion had its lid closed and was shaken until everything was mixed. A 100 microliter pipette was used to transfer 100 μL from the culture to the 10 mLs of broth in the tube labeled 10^ -2. 10mLs was then taken from the first test tube to the second test tube labeled 10^ -4 and so on until the last tube, 10^ -8. For the plate serial dilution, 100 μL was taken from the 10^ -2 tube and placed on the nutrient agar plate labeled 10^ -3. The sample was spread using a heated glass "L' shaped rode. Same method would be used for the rest of the plates where 10^ -4 would go into plate 10^ -5, 10^ -6 would go into plate 10^ -7, and 10^ 8 would go into plate 10^ -9. The same method would be used for the "tet" plates. The plates where then placed agar side up in a rack.

Data/Observations: When the lid was taken off the container there was a dirt like smell. The appearance was a rather brown looking color but it was not dirty enough because there was still plenty of visibility. From an aerial view of the liquid, there was mold floating on the water while the dirt and grass sank to the bottom. This image shows a side view of the Hay Infusion Culture.

The samples were taken from the top and bottom of the container. This was important because it would help show the diversity of organisms. Some organisms might prefer hanging around plants and dirt as opposed to the ones that tend to avoid them but still live in the same ecosystem. One reason for this might be that some protist need certain nutrients to consume that only a plant may carry. Were an algae would not need those nutrients because it creates its own.

This next figure shows the the organisms found and their dimensions.

The next two images are rough sketches of the organisms observed. The last image is a look at the Euplotes found.

There seemed to be an interesting pattern where little to no algae were found near the bottom of the container.

Conclusion: Based on the data, the organisms identified as algae were only at the top of the container. Mostly all the protists organisms where near the plant and at the bottom of the container. This data refutes the hypothesis. Had the Hay Infusion Culture grew for another two months I would predict that the diversity of the organisms would decrease. The frequency of certain organisms should increase meaning that organism that don't have the necessary traits to survive in the ecosystem would die. In terms of improving this experiment, it would be extremely useful to slow down the organisms a lot more.There was numerous times when the organisms would swim away making it hard to measure or identify. Also, taking picture of the organism helped confirm what an organism looked like without having to strain the eye.