User:Erin McDonough/Notebook/Biology 210 at AU

Lab 2: Hay Infusion Culture, 1/28/15

Observation of Hay Infusion: In this lab, the Hay Infusion Culture prepared in the previous lab was examined, and samples were taken for microscopic observation. The jar was filled with murky brown liquid, with silt-like matter having separated and sunk to the bottom of the jar, and some larger structures, primarily leaves, suspended in the mixture. The surface was covered in a thin film, and close to the center a small leaf touched the surface; around this leaf a white substance had formed. The mixture smelled faintly swampy. Sample 1 was taken from the surface of the Hay Infusion, close to leaf protruding at the surface, while Sample 2 was taken from matter at the bottom of the jar. Sample 1 therefore came from a niche which provided infrastructure on which organisms might live, while sample 2 was taken from an area where swimming organisms might be expected.

Microscopic Observation: Wet mounts were made of the two samples, and observed under the microscope; protozoa were the primary organisms identified, although some organisms that were likely bacteria were also noted. In sample 1, three protozoa were identified: colpidium (70 micrometers), pandorina (65 miocrometers), and amoeba (300 micrometers). A large number of rapidly moving organisms 1-2 micrometers in size were also noted and presumed to be spirillum bacteria. Sample 2 contained pandorina (35 micormeters), colpidium (70 micrometers), and paramecium (125 micrometers). In both samples, the colpidium were very fast-moving. The paramecium was also fast moving, while the amoeba moved through slow extension of "legs." The pandorina in both samples were motile, but did not move much; in sample one, the pandorina was bound on all sides by leaf matter, and spun in place, while in sample 2 the pandorina did not exhibit much motion at all.

Drawings of Protozoa Viewed in Samples 1&2:

Meeting the Needs for Life: All of these organisms meet the needs of life: all consist of cells, process information, acquire and use energy, and replicate and evolve as species. The observed bacteria appeared to be unicellular, while the colpidium, pandorina, amoeba, and paramecium were all multicellular organisms. All organisms observed moved, suggesting that they were able to acquire and use energy. Additionally, the movement of the various organisms observed appeared to correspond with environmental factors, such as the presence of other organisms or inorganic matter, suggesting that these organisms are indeed processing information (in addition to passing on information through DNA replication). Although replication was not observed during this lab, and evolution cannot be observed in individuals, all the organisms identified are known to replicate and evolve as species.

Ideas for Further Study: Following inspection of the samples from the Hay Infusion Culture, the culture was mixed and the mixture used to inoculate 4 agar nutrient plates and 4 tetracycline plates. If the Hay Infusion were allowed to sit for 2 months, it is likely that more differences would be noted in samples taken from diverse parts of the culture. While sampling after one week showed copidium and pandorina, both highly motile organisms, in both samples, it is likely that after 2 months niches that provide more structure, such as the niche from which sample 1 was taken, would exhibit more organisms like amoeba, with organisms that are more adept swimmers dominating niches like that of sample 2.

--Erin McDonough 09:02, 29 January 2015 (EST)

1.27.15 Excellent first entry. Could include headings: Purpose, Materials & Methods etc. SK

Lab 1: Transect Observation and Sample Taking, 1/26/15

The transect under observation for this lab was a roughly 20 by 20 meter trapezoidal plot, in the middle of the Eric Friedheim Quadrangle at American University; as such, this transect is often traversed, possibly even more so than other parts of the quad, as it lies right next to a path, which forms the southwest border of the plot. From this transect, a sample including both organic and inorganic matter was taken, from which a Hay Infusion Culture was created.

The transect's chief abiotic components include dirt, which forms a planter along the west edge of the transect, patches of ice and snow, and a stone and concrete wall that protrudes into the north-most corner of the transect. A plastic fork was also found just outside the eastern bounds of the transect, suggesting that trash cast aside by students may regularly be cast into the transect. Chief biotic components include rose bushes in the planter along the west edge of the transect, long grass planted beneath them, and another set of bushes (which also flower during warmer months) around the concrete and stone wall in the north corner; both sets of bushes have few, brown leaves, almost as though dead; however, both are perennials and therefore will likely become fuller with the return of warmer weather. Underneath these plants there are many dead leaves, particularly piled up along the edge where the planter meets the grass; these come from a large oak tree that overshadows the transect (east of the transect). Within the planter are also small sticks, wood-chips that appear to be left-over from when the planter was last mulched, and a variety of weeds. The rest of the plot, which forms the majority of the transect, is covered in short grass, with a few weeds interspersed; the grass is currently rather patchy, likely from a combination of trampling and recent weather, which has been cold and icy. The soil throughout the transect is damp. The transect is largely flat, with the planter slightly elevated above the surrounding grass.

The sample to be used for the Hay Infusion culture was taken primarily from the border between the planter and the grass, near the rose bushes, as indicated on the drawing below. The sample included dirt, dead leaves from the oak tree, grass, weeds, and leaves from the rose bush (including one thorn). A long grass from further beneath the rose bushes was also included in the sample, as well as leaves from the dead plants in the north corner. 12 grams of the sample were placed in a plastic jar, along with 500 mL of deerpark water and 0.1 gm dried milk, the lid was put on the jar, and the sample was gently mixed for about 10 seconds. The lid was then removed and the jar was placed on a table in the lab to incubate for 1 week.

Drawing of an Aerial View of Transect:

--Erin McDonough 22:59, 26 January 2015 (EST)

First entry, 1/22/15

Testing