User:Leo G. Brody/Notebook/Biology 210 at AU

Lab 1-Transect Analysis (1/13/2016): The 20 X 20 transect that our group (group 3) was assigned is located next to the amphitheater. The transect is a small creek, about a meter across and five inches deep, with foliage surrounding it. Abiotic Components: 1.) Rocks- in the creek and soil 2.) Water- in the creek 3.) Clay- near the banks of the creek 4.) Litter- scattered throughout the transect 5.) Concrete- blocks of it in the creek. Biotic Components: 1.) Ivy- located throughout the transect 2.) wild onion- around the edge of the creek 3.) flowers- near the sidewalk 4.) birds- nesting in the trees within the transect 5.) insects- within the dirt and on the surface of the water.

Picture of aerial view of transect:

Picture of transect:

Lab 2 "Protists" (1/27/2016:The hay infusion culture had an acrid smell and the liquid within was black with a filmy surface. The plant matter within the jar were far decayed, and had turned shades of brown and black. The rotting onion root likely contributed to most of the foul smell. Mold was prevalent throughout the sample, especially on the surface. The mold growing on the plant matter is likely different than the mold that fed on the dried milk solution. It was hypothesized that the life at the bottom of the jar would be more diverse and numerous.

After counting (estimating) the number of colonies on the week-old dilution plates, the results were recorded and found to be surprising. The nutrient plates not containing tetracycline had colonies, but they were not numerous and clustered enough to be visible. The diluted nutrient plates containing tetracycline starkly contrasted the others in that their colonies were large, colorful, and numbered in the dozens to even hundreds. The following trend in the number of colonies on the tetracycline (tet) plates was noticed- (10^-3): hundreds, (10^-5): hundreds, (10^-7): ~50, (10^-9): ~40. We expected the number to colonies to decrease with increasing dilution, however we did not expect to see less colonies on the plate that did not contain the antibiotic. The bacteria in the 10^-3 and 10^-5 tet dilutions were likely able to survive the antibiotics because they were able to spread out and develop a resistance. As for the nutrient plates lacking tet, finding a hypothesis for their small numbers proved more difficult. It may be that the lack of antibiotic led to very large colonies of bacteria that began to compete for food, and over time sustained large losses in population due to scarcity and natural selection. Simply put, the tet plate colonies were not compelled by their environment to compete for space and food as much.

Research on tetracycline resistant bacteria has discovered that tet resistance is often the result of bacteria acquiring new genes which code for proteins that protect essential ribosomes from the antibiotic. Bacteria may also develop resistance from random mutation. The way in which tet operates is that it inhibits protein synthesis within bacterial ribosomes.

Source: Chopra, I., & Roberts, M. (2001). Tetracycline Antibiotics: Mode of Action, Applications, Molecular Biology, and Epidemiology of Bacterial Resistance. Microbiology and Molecular Biology Reviews, 65(2), 232–260

Nutrient control 10^-5

Nutrient control 10^-9

Nutrient + tet 10^-5

Nutrient + tet 10^-9

Lab 3-Plants: The plants we gathered from the transect were ferns, leaves, seed pods, and dark mosses. Transect Sample Plants Location in transect Description Vascularization Mechanisms of Reproduction

1. 1 Creek Bank Fern yes Lack flowers/seeds
2. 2 Tree Branch Three red leaves yes Seed pods
3. 3 Creek Bank Moss no spores
4. 4 soil Seed Pod no seed
5. 5 soil Green leaf yes seed