User:Elizabeth Pouya/Notebook/Biology 210 at AU
PHOTOS FROM LAB WITH DESCRIPTIONS: http://www.flickr.com/photos/116740424@N07/
2/15: LAB 3 It is not likely that Archaea species will grow on the agar plates because they don’t provide suitable living conditions for them. For example: extremophiles which require a climate of extremely hot or extremely cold temperatures; the agar plates were placed in room temperature. The agar gel only supports the growth of certain types of prokaryotic colonies. The appearance/smell of the hay infusion might change from week to week because mold/fungi may start to develop which requires food but may also be a food source to the bacteria. So cycle of food within the ecosystem is constantly adjusting due to the growth of new organisms. Dilution (plate label) Agar Colonies Counted Conversion Factor Colonies/mL 10-3 nutrient 50 X103 50000 10-5 nutrient 5 X105 500000 10-7 nutrient 1 X107 10000000 10-9 nutrient 0 X109 0 10-3 nutrient + tet 0 X103 0 10-5 nutrient + tet 0 X105 0 10-7 nutrient + tet 11 X107 110000000 Bacterial growth appears to be evident on both the regular agar plates and the ones with antibiotic. However, the plates without antibiotic appear to have more growth. There was only growth on one of the plates with antibiotic (10-7).This indicates that the bacteria on the 10-7 were antibiotic resistant whereas the other two plates with antibiotic on them (10-3 and 10-5) were unable to grow in the presence of bacteria.Overall, the tetracycline either causes zero colonies to grow in its presence or it allows bacteria to grow if it is resistant to it. Only one species was unaffected by tetracycline (the plate with 10-7 dilution) - the one plate that did grow bacteria in the presence of tetracycline grew more colonies of bacteria than any of the other non-tetracycline plates (as shown in the table). Tetracycline mainly works by interfering with the ability of bacteria to produce proteins that are essential for their growth and replication (prevents introduction of new amino acids to the peptide chain). So tetracycline does not kill bacteria, it simply inhibits them from reproducing. Mammalian cells are less vulnerable to the effect of tetracyclines, because bacteria actively pump tetracycline into their cytoplasm – whereas mammalian cells do not. Tetracyclines are effective against both Gram-positive and Gram-negative cells, more specifically: H. pylori, E. Coli, M. tuberculosis, and P. aerugonisa. 10-5 : branches, entire edge, and no elevation 10-7 :circular form, colonies are an orange color, filamentous form and margin, raised elevation 107 :circular form, entire margin, raised elevation 10-3: irregular form, undulate edge, no elevation
2/7: LAB 2 The culture is not completely lacking in scent—it’s faint, but slightly there. There appears to be a very thin layer of ‘film’ on top (show in the pictures). The rest of the culture is mainly a muddy color; there is a lot of dirt collected on the bottom along with the leaves and a few branches. Colpidium ~45µm, mobile, looks as if it is vibrating back and forth very fast, have cilia Paramecium aurelia ~130µm, mobile and moves slowly and demonstrates inching motion (contracts horizontally and vertically in order to move itself – uses ATP for this process) Chlamydomonas ~4.5µm, mobile, has two flagella that propel it very quickly Middle of Culture: Unknown Organism ~75µm, has a single long flagella that is attached to a plant leaf. The flagella contracts as the rest of the organism is pulled in and let go. Possibly Parenema sp. Paramecium multimicronucleatum ~200µ, mobile and moves slowly (floats) Colpidium ~45µm Top of Culture: Clamydomonas ~6µm Paramecium caudatum ~250µm, mobile and moves slowly (floats) Colpidium ~50µm The chlamydomas was a species that appeared frequently within all layers of our hay infusion culture. The chlamydomonas is a genus of green algae that has unicellular flagellates/ It’s typically found in stagnant water and damp soil (both a part of our hay infusion culture.) The chlamydomas uses energy, specifically ATP in order to power its flagella. It is also made of a single cell which includes chloroplasts (has the ability to photosynthesize – ATP also required). This organism hosts information within the cell because it has DNA which is capable of replicating itself. And lastly, chlamydomonas’ lineage diverged from land plants over 1 billion years ago so it had demonstrated that it is capable f evolving. Had the hay infusion culture been observed for another two months then I would predict that different types of organisms would continue to grow. For example, given the diversity of bacteria and nutrients found in the culture (large food supply) it is possible that mold or possibly even fungi would begin to grow. And with the presence of new organisms, we would also be able to observe new kinds of bacteria.
Selective pressures that affected could have affected the composition of our sample are the availability and variety of nutrients available for the organisms. Also, the number of leafs plant-type factors that were initially put into the hay infusion culture.
1/29: LAB 1 Transect: Mini Marsh The transect is slightly elevated and on a slope. Part of it is adjacent to the sidewalk and directly across Kogod School of Business. Immediately next to the boundaries of the transect, there is a sewage drain. There is some shade from very large trees that are approximately 20 feet away, however, most of the transect is exposed to the sun when present. Majority of the plants within the transect are dry and unlively however the area under all of the little rocks is very damp. Within this transect, there is a variety of plants (as shown in the picture.) The transect is also an area that is maintained by the university so fertilizers are used on the plants and the grass is cut by a lawnmower. Abiotic Factors: little rocks, big rocks, cement brick. Random piece of metal, gum wrapper, and a cigarette. Biotic Factors: cat tails, grass, leaves, bushes, soil, squirrels, snakes, rates, worms, and trees in close proximity We sampled some of the dirt, grass roots, leaves, and different plants in order to make our Hay Infusion culture. Although now covered in snow, pictures of the Mini Marsh transect are shown below.