Writing in Biology

Vasopressin is a neurotransmitter that synapses on V1a receptors in the brain that provide the prairie vole (PV) with positive feedback for its monogamous mating behavior.  This V1a receptor is encoded by the avpr1a gene, which contains more DNA material in the PV than in the meadow vole and might account for more abundant V1a receptors in the prairie vole brain.  In order to test this hypothesis, the researchers inserted extra copies of the avpr1a gene into male PVs to see if more V1a receptors were produced.  The male PV with extra receptors did form stronger relationships with females, even if they had not previously mated with them proving this genes significance in PV monogamy

Using a simple planarian trap to capture planarians, we selected eight locations local to the University of Massachusetts Amherst, to set up the planarian traps. Upon collection of the specimens at these different locations, along with the observation of the any vegetation, deadfall, sunlight, water flow speed,and soil make up, we will identify the different species of planarians using size, color and head shape. Once identified, we will observe if there is a correlation between the species that inhabit the body of water with the environmental and aquatic characteristics mentioned, or if there is no correlation between these variables. In the end determining two main points, the species richness and diversity and if it correlates with environmental factors or not.

It is possible rate of cellular movement will follow the predictions made in our hypothesis, or that it will not. The average rate at which cells migrate in order to heal the wound could be roughly the same throughout the entire process. Additionally, there could be a large discrepancy in rates of cells based on their position relative to the wound, in which case studying average rate of movement over time would not be an effective way to capture cellular movement rate.

              Displacement patterns in cellular movement across the wound could follow the predictions made in our hypothesis, or could demonstrate large differences in total displacement over time, based on a cells location relative to the wound. It is possible that cells closer to the wound will move a greater distance over time than cells further away from the wound.

For the microbial growth lab, I hypothesized that E.coli, would have the best optimal growth at 37 degrees celsius, as this is the desired temperature for E. coli growth, especially in the cells of humans, animals, and other eukaryotic organisms. I also expect that the k value for 37 degrees celsius which indicates the rate of how many generations occur per time period to be the highest because, it will form the most generations, and the G value which indicates the rate of one cell dividing into two cells to be the lowest because E.coli will divide the fastest at 37° celsius.

For experiment 1, the data suggest that the type of substrate did indeed affect survival of
guppies, which altered spot brightness over time. The muddy substrate had the largest average
increase in spot brightness, 3.5. The vegetative substrate had the smallest average increase in
spot brightness, 2.0 and sandy substrate had an increase of 3.0.

For experiment 2, the data suggest that as predation increases, the spot brightness of
guppies decreases over time. For the trial with no predators, there was an average increase in
spot brightness of 7.0. For the highest level of predation, there was an average decrease in spot
brightness of 1.5. All 3 other trials of varying predation levels also support the hypothesis.

3-methyl- 1-butanol and propionic acid were reacted with each other in an esterification process in hopes of synthesizing isopentylpropionate. The procedure described above was followed without error and the isopentylpropionate was synthesized with a 62.04% yield. The final liquid had a fruity scent similar to that of bananas. The IR graph supports the purity of the compound considering the peaks that correspond with an ester at 1739.79 and a carboxylic acid 2958.8. However there is no peak corresponding with an alcohol group, which is expected because isopentylpropionate does not have an alcohol group.

.97 mL of propionic acid and 1.19 mL of 3- methyl- 1- butanol were added to a 5 mL round bottom flask. 4 drops of sulfuric acid were then added to the flask and the contents were thoroughly mixed. Boiling chips were added to the flask and the flask was attached to the distillation head and placed a 45 degree angle on the sand bath. The flask was brought to a slight flask for 15 minutes. After 15 minutes the contents of the side arm were gently poured back into the flask, being sure that no water was returned. This process was repeated two more times, after which the mixture was allowed to cool. 1 mL of water was added to the mixture and mixed thoroughly, the aqueous layer was removed and placed in the waste beaker. 1 mL of sodium bicarbonate was then added and mixed in thoroughly before removing the aqueous layer again. This process was repeated once more. Then 1 mL of saturated aqueous sodium chloride was added, mixed and the aqueous layer was removed one final time. A dozen anhydrous CaCl2 spheres were added to the mixture and the mixture was allowed to “dry” for 10 minutes. The remaining liquid after the 10 minutes was removed via pipet and put into a dry tarred vial. The weight, smell, percent yield and IR graph were all obtained and recorded for the remaining liquid.

Clearly, the use of ADHD medication illegally, to enhance academic performance becomes an arms race of who is, and who isn’t taking the drugs. If you aren’t using the cognitive enhancing medication, you put yourself at a major disadvantage. Using these drugs becomes a moral issue firstly because it gives those who take it an unfair advantage. But to go further, these enhancements are also morally wrong because it would likely lead to more difficult course requirements. Just as in sports with anabolic steroids, the issue becomes one of deciding to take the moral path and suffer statistically, or to use enhancements to be at the top.

LLC-Pk1 parental cells will be cultured and plated in dishes. These cells will then be allowed to grow and divide until they are at confluent levels. Once the cells are confluent, a scratch assay will be conducted in which a small portion of the cells are scraped from the plate, creating a small and consistent gap between two large patches of cells. The cells are then washed twice with HBS and submerged in non-CO_2­ media. They are then observed under phase microscopy at 10X magnification in a time-lapse fashion. The migration of the cells into the “wound” will then be captured and analyzed. Rate of cellular migration and length of time it took for the wound to close will be parameters analyzed. 

Cell migration is a fundamental and crucial component in the survival and maintenance of multicellular organisms. Organisms rely on cellular migration during embryonic development and immune responses in order to correctly organize and heal tissues within the body. Investigation into the mechanisms by which cells migrate is essential in understanding these important processes.

              One way in which cell migration dynamics can be studied is via a scratch (or wound) assay. It is done in-vitro, but greatly mimics, a cells migratory pattern in-vivo. Cells that naturally form monolayers, such as epithelial cells, are exemplary to use in this type of assay as the cells behave analogously in-vitro. The assay is done by scraping a small portion of the layer of cells off of the plate, creating a gap in between cells that were once touching in the monolayer, mimicking an epithelial “wound”. The cells are then visualized and allowed to migrate into the space where cells were scraped off of the plate, thus closing the gap and “healing the wound”. The migratory pattern that cells exhibit during this time is studied and analyzed for important parameters, such as rate and total displacement. Investigating these factors of cell migration in epithelial cells is important in order to better understand mechanisms behind the healing of epithelial abrasions, which affect a large majority of organisms.

              We predict that rate of cellular movement will not be constant but will have a steady increase in rate over time as the wound healing process goes on, and slow as the wound is close to healed. The change in rate over time will be graphically reminiscent of a normal curve. Additionally. we predict that all migrating cells will have a similar average displacement over time as they fill the wound.