Writing in Biology

As many know, reaction time is a measure of how quickly an animal can react to a stimulus, this involves the time that your brain can process and take action. Three main stimulouses are visual, auditory, and tactile, tactile being a physical contact. The quickest reaction time of the three usually being tactile. A tactile stimulus this is the fastest is because we have many sensors all throughout our body which enable us to react faster when we receive a stimulus compared to auditory and visual which both require more processing done by the brain. An examply of this is when we place our hand on a hot stove and almost immediately rectract our hand before serious damage can be done. A tactile stimulant moves through the nerve at about 390 feet per second which is the reason why we are able to respond in such little time. Visual and auditory stimulous has a larger processing time than tactile because for each, you first need to recieve the stimulus and then the information has to be processed by the brain and differentiate between a danger stimulus or a regular stimulus. Reaction time is also influenced by many factors. Sleep could impact the reaction time of an individual. If an individual is not getting enough, their reaction time will decrease because their body is lacking awareness and energy needed for the reaction time. In contrast, stimulants such as caffeine or drugs that increase your alertness or heart rate will have the opposite of lack of sleep. These will increase your reaction time because it increases your alertness which makes you more susceptible to processing stimulus faster.

In this lab, cyclohexanol was distilled with a phosphoric acid catalyst, giving a 35.9 % yield of cyclohexene. After the putting the test sample of my product in the gas chamber (GC), the result should that the product obtained was in fact cyclohexene. The standard GC graph shows a retention time at 0.205. The GC graph obtained from the cyclohexene product showed a retention time of 0.175, which is not much different than the standard. The IR analysis showed the results have a major dip between 3200 and 2800 l/cm. The standard IR analysis shows a dip from 3061.03 to 2837.29 l/cm. The results obtained are a clear indicator that the product was cyclohexene. There is a dip at 1635.00 l/cm indicates that there is a double bond in the product. Since there is lack of a dip between 3400 to 3200, which would indicate alcohol is present, my product does not contain alcohol. After these two methods of analysis, the results can confirm that the product was indeed cyclohexene.

Finally, it was washed with brine (1 x 1.5 mL). After each wash, the lower layer was moved to a waste beaker. After washing, CaCl2 pellets were added to the vial until the pellets stopped clumping together. It was left for five minutes to dry and the dried product was transferred to a new vial. The final product (0.652g, 49.9%) was divided so further tests like GC, IR and bromine and potassium permanganate chemical tests could be performed. The bromine in dichloromethane (3% solution) was added one drop at a time and the color changes were observed after each drop. The same method was carried out with potassium permanganate (1% potassium permanganate and 10% sulfuric acid). Color changes were recorded after each drop.

Social Rank: Social conflict increases stress hormone levels, such as glucocorticoid, and has other associated costs on the body’s function. To mitigate this effect,  birds have developed a system that is dependent on the dominance of alphas and the subordinate social status of the subordinate individuals. These rankings are often established through physical contest and reinforced by threatening behavior as well as submissive posturing of the inferior specimens. Several factors, including age, parasite load,  physiology and sex all determine status and these figures typically have greater access to food or mates as well as decreased risk of predation. Furthermore, as evidence suggests, birds are able to differentiate individuals based on heritable features such as plumage, size, behavior and voice.

Flocks: Range from temporary, less orderly aggregations to organized foraging associations involving multiple species. These groups can be simple and focus on localized nesting areas, or opportunistic feeding grounds, as well as more intricate social system. Flocks are flexible systems that are defined by several tradeoffs. Benefits include predation risk secondary to statistical improvement as well as additional alerting neighbors as well as increased foraging efficiency as birds are able to share information to utilize their specialties. Flocks can utilize the “Beater Effect” , where decoy predators will flush out prey for the rest of the flock, as well as the more classic rounding up of prey seen in sea birds. However, this system is not without drawbacks as there are increased demand for food supplies, higher rates of disease and increased levels of aggression to maintain a personal space and metabolic needs.  In addition, due to their intrinsically selfish,self fulfilling nature, there are “scrounger” individuals who will benefit from the “producer” birds without contributing. These individuals are a net negative and offer no additional benefit to the flock, further increasing the demand of the flock.

    To a 10 mL round bottom flask cyclohexanol (2.004g, 20mmol) and phosphoric acid (0.5 mL, 85% purity) was added. The round bottom flask was then attached to a fractional distillation apparatus and lowered into a heated sand bath (40 °C). The mixture was heated so that one drop collected in the distillation vial every 20-30 seconds. When ~10% of the original mixture was left, the round-bottomed flask was removed from the heat. The flask was then left to cool for the dehydration phase of the experiment. Using a pipet and expelling back and forth the product was removed from the round bottom flask into a test tube to start the dehydration process. The cyclohexene was washed with water (1 X 1.0mL). Next it was washed with 1M NaOH (1 x 1.0 mL).

The target product of cyclohexene was obtained through a dehydration reaction of cyclohexanol using 80% phosphoric acid as a catalyst and resulted in a 47% yield.  A fractional distillation column was used to separate the cyclohexene product from the remaining phosphoric acid and impurities.  The cyclohexene was purified at a boiling point (64 °C), which is far lower than the documented boiling point of cyclohexanol starting material.  The presence of cyclohexene was confirmed from the characterization analyses preformed.

Cyclohexanol dehydrates to yield cyclohexene in a one to one ratio.  Cyclohexanol (1.99 g) was used as a starting material and therefore should have yielded cyclohexene (1.64 g).  The actual yield of cyclohexene was 0.77 g, which gives a percent yield of 47%.  The low yield is most likely due to low-boiling components of cyclohexene and water that leave some product behind in the flask and in the column.  Using a high-boiling component, such as toluene, to continue the distillation, would most likely have helped recover product.  However, by eliminating this step, it greatly reduced the time spent on the experiment.

The petunias displayed many differences and the syndromes were split into phenotypic and genetic components. Several differences were spotted including cell-growth and cell-division patterns in the basal third of the petals, longer ventral stamens, nectar production and metabolism, and enzymatic differentiation in the phenylpropanoid pathway. P. hybrids was studied and one to five tries that could be measured quantitively were identified for a syndrome component. Stamen elongation and nectar volume had large allelic differences. All of this data can provide valuable information for understanding floral syndromes.

All through the controversy and misunderstanding, scientists still fight for the consensus of embryonic stem cell research. Political action has also been taken towards stem cell research as policies have been put in place to limit research. Basic requirements such as informed consent on obtaining embryos for research have been added to help respect the diverse views on the topic. The procedure for obtaining the embryos has come under backlash as the early embryo has to be destroyed in stem cell research, this infuriates those who are against the research. However the embryos used for the research are often donated from in-vitro fertilization clinics, mostly from failed implantations or from excess embryos that would have been eventually destroyed due to overstock. These lines or limitations on the embryonic stem cell research have been ordered under both the Bush administration and recently under the Obama administration.

Another example of an ecosystem engineer is the gopher tortoise. The gopher tortoise is a species of tortoise that lives in the southeastern united states. Since reptiles are cold blooded, they usually hide in the shade when the sun is too hot. However, gopher tortoises dig tunnels in order to escape the hot rays of the sun. These tortoises dig complex pathways in which they can rest while the sun is too hot. Interestingly, other animals use these tunnels as well. For example, rattlesnakes have been seen hiding in the tunnels right along side the tortoise. Because the tortoise is armored, it doesn’t have to worry about the rattlesnake attacking it. In addition to protection from the sun, tortoise tunnels serve as an escape for forest fires. In dry, woodland environments where fires are frequent, animals of all kinds can take refuge in the tortoise tunnels until the flames die down. For example, armadillos have been seen to be hiding in these tunnels.