Drafts

Solubility is the chemical property which refers to how much a solute will dissolve in the solvent. Polar compounds dissolve better in polar solvents, while non-polar compounds dissolve better in non-polar solvents. This is why the best solvent in the experiment for non-polar benzil is hexane because it is also non-polar. In addition, non-polar compounds have lower melting points since electronegativity is lower.

The first part of the experiment was spent finding the best solvent. It had to be insoluble at room temperature, soluble at boiling point, and crystalize in ice. Hexane was found to be the best solvent.

The next part of the lab was to recrystallize phthalic acid. It was dissolved in water, boiled, then placed in an ice bath to crystallize. Once the crystals formed, it was filtered to separate the impurities from the compound. Finally, recrystallization had to be performed for the unknown 6 and then calculate the melting point. The same procedure used to recrystallize and filter the phthalic acid was used for the unknown 6. The crystals were left to dry for five days and measured. The melting point of unknown 6 was 96 degrees celsius, which concluded to be benzil.

The methods project required students to create a multi-panel scientific figure of an interspecific interaction. A methods section was then created by the student to describe in detail how to replicate the figure created. The purpose of the project was to be able to see if the methods that were written could lead to an accurate replication of the multi-panel figure created. There were three separate panels in the figure that consisted of lichen and a tree. The differences observed in this figure was of background, color, and labeling. These differences were a result from the differences in weather and positioning of the photo.

As part of the the Writing in Biology class of Spring 2019 in University of Massachusetts Amherst I had to create a multi-panel figure that depicted an interspecific interaction that was replicable. The majority of scientific articles include a methods section, this section allows other scientists to replicate the results that were obtained in the original article. The purpose of this project is to help develop the skills needed to write a thorough methods that can be replicated. In this project, the interspecific interaction between a lichen and a maple red tree will be photographed.

The damages inflicted by biological extinction left us with a deep pain that appeared irremediable. However, in recent years, the possibility has been broached that something can be done, but at what cost? Species negatively introduced in past decades by humans have lead to the widespread loss of habitat and the killing of large numbers of endemic species. In fact, “invasive species have contributed directly to the decline of 42% of the threatened and endangered species in the United States. The annual cost to the United States economy is estimated at $120 billion a year… with the annual cost of impacts and control efforts equaling five percent of the world’s economy” (Impacts of Invasive Species, 2017). The purpose of de-extinction is a tool to bring back genetically-similar animals that went extinct to help balance the loss of the original species to ecosystems. Invasive species are problematic pests that use up resources which native species then must directly compete against; therefore we should only be introducing new species if they do not negatively influence the niches of co-existing species.

Factors that may have impacted the results are the weather, the distance from the tree, and the camera angle. The weather may have played a role in impacting the colors and contrast of the tree and moss. The original photos were taken on a muggy day before there was any snowfall. The replicate photo was taken with snowfall on the ground; the tree looks drier and the moss is not as clearly seen. The white snow could have caused the phone brightness to be greater thus resulting in the poor contrast between the moss and the tree. The distance from the tree could play a part in why the tree appears larger in the original photos than in the replicate. The replicate photos were most likely taken from a slightly greater distance from the tree causing the tree to appear smaller and the background to appear larger. The angle of the camera may have caused the proportion of the tree to be larger at the top than in the bottom in the replicate. It also may have caused some of the background differences, like the presence of the library. 

Neanderthals and Denisovans were prehistoric humans. Neanderthals lived in Euope and Western Asia about four hundred thousand years ago and were extinct fourty thousand years ago. A distantly related group called the Denisovans originated in Asia. Evidence suggests that modern humans and prehistoric humans overlapped for a period suggesting interbreeding. DNA evidence reveals that there are parts of the human genome shared with the prehistoric humans. In modern African populations, the ressemblence between Africans and Neanderthals is nearly zero or zero, but is found to be at one or two percent in populations from Europe and Asia. Denisovan DNA is found to be lower than four to six percent in Asian populations and undetectable in other parts of the world. The genetic information found from prehistoric humans reveals the differences between modern humans and extinct prehistoric humans. It also reveals that certain variations in phenotypes and to some extent, risk of diseases (though still under study) may be identified. This however, does not reveal how "evolved" modern humans are, nor does it reveal practical information on assessing individual's health.

Anxiety and panic disorders are related to an imbalance in excitatory and inhibitory neurotransmitters. Deep brain stimulation is the process of using electrodes to stimulate the brain. The electrodes send impulses which can create certain signals when stimulated. The experiment was conducted on mice. The anxiety of mice was measured in a maze. The next step was using deep brain stimulation on one group of mice. When both groups of mice were put into the maze again. The mice that received deep brain stimulation was showing lower signs of anxiety and panic. The results of the study shows that using deep brain stimulation can be a way to reduce anxiety and panic in people.

Flight is an adaptation taken by Class of Aves. They are the only Class that can fly and the latest aircrafts cannot beat the accuracy of bird flight. Flying is done in several steps to be completed and every flight step requires the bird to know how to adjust their wings against the wind and gravity. The acute sensory system is vital in flight to detect the smallest changes to maintain balance in the air. Chapter five covers the principles of aerodynamics and how they differ among different types of flight strategies.

Retinitis pigmentosa is a genetic condition where the photoreceptors of the eye are destroyed. Which causes the people with this disease blind. Optogenetics are proteins that are introduced to control light. The use of optogenetics are typically used as signals from photoreceptors to the brain. When a person see a light of a certain color, it can be traced with optogenetics and with that knowledged opsin proteins can be used to help people regain so vision. The opsin proteins will cause the neurons to fire and action potential. Overall, it is a way people are able to regain some of their vision. Though people are different and sometimes there may be too much damage to repair.

While much time and energy has been depleted discussing how it would be accomplished and which species would serve as practical candidates for de-extinction, there has been little talk about how species would be reintroduced into the wild, or if it even has a place anymore. If an ecosystem has been altered significantly since a species went extinct, a reintroduced species could wreak havoc on existing species. De-extinct species would be alien and potentially invasive when introduced to their primitive terrans, resulting in further devastation to already crumbling ecosystems. Both old habitats and food sources have changed in their absence; therefore de-extinct species’ roles in these ecosystems have transformed as well. Passenger pigeons, which are a primary candidate for de-extinction, served as a keystone species and major food source for carnivores including foxes, lynx, raccoons, marten and mink, falcons, and hawks in North America during early 1800s (The Passenger Pigeon, Craig Kasnoff, 2017). Sadly, these beautiful birds were reduced to their last individual Martha who died in 1914- more than a century passing since their total demise. The environment has learned to exist without them, as this is more than a substantial amount of time for its natural environment to adapt to new resources in their absence. The truth of the matter is, the passenger pigeon’s homeland will be unrecognizable- the environment does not need passenger pigeons anymore, yet de-extinction would mean reintroducing them to a new world that does not need them. Some scientists suggest the use of self-contained mini ecosystems to gage how a resurrected species might interact with existing ones. This would be conducted under extremely controlled conditions where scientists can predict the safety to reintroducing the species to the target environment. However this would unfortunately only provide a broad estimate, and under the unpredictability and utter harshness of the natural world we cannot predict exactly what will happen when we release these hybrids to the delicate fabrication of the wild. If these new, genetically modified birds become invasive to U.S. lands, the damage will be irreversible. There are no “maybes” to such a precise decision, it either must be executed correctly and just, or not until we have concrete evidence of the benefits de-extinction holds first.

This is my lab write for an endospore experiment.

Expected Results:

The expected results were to find gram positive endospores that survived pasteurization at 70 degrees celsius. Isolation of endospores was expected because microorganisms were being isolated from a soil sample. Soil is relatively low in nutrients and nutrient deprivation is what causes endospores to form. Some bacteria have the ability to produce endospores by sporulation. Because endospores are dehydrated (leaving them metabolically inactive) and covered in a thick layer consisting of peptidoglycan and proteins, they are able to withstand high temperatures. The soil samples were pasteurized at 70 degrees celsius in hopes that all vegetative cells would be killed and only protected endospores would be left. The endospores were expected to be gram positive due to their thick peptidoglycan layer, a defining characteristic of gram positive organisms.      

Observed Results:

The pre-pasteurization plate resulted in a lawn. There was no isolation. There were different colored colonies, white, grey, and beige, these colonies were not isolated there was a change in color across the lawn. The post-pasteurization plate resulted in minimal isolation. The were four separate isolated colony types, white rhizoid, white circular (this colony was used for gram stain and phase contrast microscopy), white irregular, and a milky beige irregular colony. After conducting a gram stain and viewing the slides under a light microscope, the stained cells appeared as purple bacilli. The wet mount (which used cells from the same isolated colony as the gram stain) when viewed under a phase contrast microscope resembled bacilli with a circle inside of it. The resulting cells fit the description of a sub-terminal endospore.   

Conclusion:

The observed results were consistent with expected results. Gram positive endospores were expected to be isolated after pasteurization and they were. When observed under a microscope the cells appeared to be sub-terminal endospores. From the performed experiments we can conclude that soil does contain gram positive endospores. We can also confirm that pasteurizing the soil will still result in undamaged endospores demonstrating that they are heat resistant.