User:Student 68/Notebook/Biology 210 at AU

January 28, 2016: Identifying Bacteria in a Transect

Purpose: The purpose of this lab was to study different types of bacteria and analyze whether the samples were gram positive or negative. Furthermore, the growth in each sample, based on the amount of tetracycline added, was evaluated. The group hypothesized that the bacteria samples with less dilutions would result in more growth.

Materials and Methods: In the week prior to this experiment, eight bacteria samples were taken from the hay infusion culture. In four of the samples, nutrients without tetracycline were added with labels 10-2, 10-4, 10-6, and 10-8. The same procedure was performed with another four bacterial plates, but tetracycline was added to these cultures. After incubating for a week, the bacteria grew within each plate. Using the four samples which held the most growth (2 non-tet and 2 +tet), small samples of each were taken and put onto a microscope slide. In this instance, the 10-2 and 10-4 samples were used. This was performed by sterilizing a loop over a flame, scraping a small amount of growth, and then initiating the gram stain procedure. A drop of water was added to each slide and then placed onto the staining tray. Crystal violet was added for a minute, rinsed off, and then followed by Gram's iodine, 95% alcohol, and then safranin. Each stain was removed with water before the next was added. After this process was done, each slide was wiped off, ready to be observed in the microscope.

Observations and Data:

This image shows the 10-3 and 10-5 serial dilutions without tetracycline.

This is the 10^-5 dilution with tetracycline.

This is the 10^-7 dilution with tetracycline.

This is the 10^-3 dilution with tetracycline.

These are the 10^-9 bacterial samples that did not grow.

Table for bacterial colony results: Nutrient dilutions: 10^-3 -- 1,100 colonies, 10^3 conversion factor, 11000 colonies/mL 10^-5 -- 85 colonies, 10^5 conversion factor, 850 colonies/mL 10^-7 -- 0 colonies, 10^7 conversion factor, 0 colonies/mL 10^-9 -- 0 colonies, 10^9 conversion factor, 0 colonies/mL

Nutrient + Tet dilutions: 10^-3 -- 1,000 colonies, 10^3 conversion factor, 10000 colonies/mL 10^-5 -- 51 colonies, 10^5 conversion factor, 510 colonies/mL 10^-7 -- 1 colony, 10^7 conversion factor, 10 colonies/mL 10^-9 -- 0 colonies, 10^9 conversion factor, 0 colonies/mL

Below show the images of the bacteria under the microscope.

This is the 10^-3 dilution without tetracycline.

This is the 10^-3 dilution with tetracycline.

This is the 10^-5 dilution with tetracycline.

This is the 10^-5 dilution without tetracycline.

Table for bacterial observations: 10-3 with nutrient:1 micrometer, round & yellow, spherical, - gram 10-5 with nutrient: 1 micrometer, round and yellow, rod, -gram 10-3 with tet: 1 micrometer yellow, spiral, -gram 10-5 with tet:1 micrometer yellow, spherical, +gram

Conclusions and Future Directions: The hypothesis was correct, as the most growth was seen in the plates with the least dilution. The data from the microscopes also revealed that there was a wide range of bacteria found in the transect, as each sample showed a different type. Going forward, the group will have to use a chart to identify the classifications of the different types of bacteria found, not just their shapes. Furthermore, research could be conducted to see if gram positive samples are less common than gram negative samples. In the experiment, more gram negative positive samples were found. It is important to note that growing bacteria with many serial dilutions will not work well.

AN

January 21, 2016: Identifying Protists taken from an Outdoor Sample

Purpose: The purpose of this lab was to classify protists found in the hay infusion sample. After extracting small samples at all levels of the sample, dichotomous key was used to categorize the types of protists represented. The group hypothesized that many different protists would be observed, as there is usually wide diversity in every environment - no matter how small.

Materials and Methods: The hay infusion sample was created by taking a sample from the transect and preserving it in a plastic bag. Placing about 10 grams of these items (soil, leaves, etc) into a plastic jar created an environment for these items to live. Following this, 500mLs of deerpark water and 0.1 grams of dried milk. A lid was temporarily placed on the jar so that the items could be mixed together, but then the lid was removed so the environment would have access to air. After a week, samples were taken from the top, middle, and bottom of the hay infusion sample. Each one was placed on a microscope slide and cover slip, then put under a microscope to observe the protists in the sample. Results were noted and the protists were identified using a dichotomous key.

Data and Observations: The hay infusion sample had a foul smell after a week. The top layer was creamy, while the middle layer was a musky brown color. At the bottom of the jar, a layer of what looked to be dark mud was sitting there. Six different protists were observed, two from each layer of the hay infusion.

This shows a side view of the hay infusion.

This displays an aerial view of the hay infusion.

Within the top layer, pandorina and difflugia were found. Both can be seen in the photo above, though they were difficult to photograph as they were very small. The pandorina was faint green and had a round shape. About 40 micrometers, it had a flagella to move. Because it was green, it can be assumed that this a type of algae that does photosynthesis. On the other hand, diffuglia is a protist. It was brown in color and had an oval shape. Measuring 150 micrometers, it moved very slowly.

In the middle layer, paramecium and euglena were observed. Above, the paramecium is displayed. It was green and 30 micrometers. It moved very quickly because of its many cilia. Paramecium is a protist.

Above displays a drawing of the euglena, as it was hard to capture on the microscope. It measured around 70 micrometers and was green with cilia. This is neither a protist or algae; it is a mixtroph.

In the third layer, colpidium and pelomyxa were observed. Both pictures are shown below (pelomyxa first). Pelomxya is a protist. It was green and had flagella, about 500 micrometers. The colpidium is also a protist, about 50 micrometers and green in color. This organism had cilia.

Conclusion and Future Directions: The data supported the hypothesis, as it allowed the group to see many types of protists. In each layer of the hay infusion, a different protist was shown. It is likely that there were many more protists and types of algae that the group did not see. Overall, it is obvious that protists can grow in varied environments. Furthermore, there is a lot of variation in the protist family. Some of the organisms were much bigger than others, for example: the pelomxya was 500 micrometers and the pandorina was only 40 micrometers. The organisms also varied in shape and color. The experiment worked because the environment was given food (the milk), sunlight, and oxygen. If the group were to repeat this experiment, it would be better to spend more time on finding usable samples so that the protists are easier to find on the microscope.

AN

January 15, 2016: Exploring a Transect at AU

Purpose: The purpose of this lab was to observe a niche on the American University campus, analyzing its abiotic and biotic factors. In order to study evolution and environment, a 20x20 outdoor area was used as an example. It is likely that there were more abiotic factors than there were biotic factors.

Materials and Methods: Materials: -pencil -paper -plastic bag -20x20 outside area labeled with sticks -method of photography (cell phone) Methods: -First, the group found its location on the American University campus. The section used for this data was section 4. -After acknowledging the area, an aerial diagram of the 20x20 space was drawn using pencil and paper. -Following the drawing, the group filled their plastic bag with abiotic and biotic factors.

Data and Observations:

This is an aerial diagram drawn with pencil. On the diagram, the directions (N,E,S,W) can be shown as well as rocks, benches, plants, and a body of water.

Besides the aerial diagram, pictures of the area were taken with a cell phone. They show the factors described previously. The transect also had a water drain, acorns on the ground, a net that covered the water, and rocks that lead a pathway throughout the whole transect. Much of the soil was moist and about half of the trees had no leaves.

Conclusions and Future Directions: Within this transect, there were many biotic and abiotic factors found. Abiotic components included soil, rocks, water, sticks, air, and sunlight. Biotic factors included bushes, flowers, trees, leaves, moss (in the water), bamboo (on the water net), grass, acorns, and squirrels (though these were not seen, there was evidence of them). In contrast with the hypothesis, more biotic factors were measured than abiotic factors. This could be because there were actually more biotic components in the area or simply that not enough abiotic components were measured. Next time, more background on abiotic factors should be researched so that more accurate data can be taken.