Writing in Biology - Section 1

Throughout history, there have been many different perspectives on brain function. The ancient Egyptians believed that the brain did not aid in any higher order function. During mummification, they would remove the brain as they thought it was an unecessary organ for the afterlife. They belived that conciousness, memory and soul was located in the heart and higher order functions travelled through the blood. This theory was adapted and altered by other scientific figures such as Andreas Vesalius, who  believed that brain fluid carried higher order functions throughout the body. Theories on brain function continued to arrise as neurobiology became a more popular area of study. Yet, it was not until the mid-1600s, when Thomas Willis officially coined the term neurobiology, that the study of the brain became a legitimized form of research. 

The idea of a gay gene has been long debated and sought after among geneticists. After years of persecution and discrimination, some members of the LGBT community support such a search, in the hopes of scrapping the argument that their way of life is unnatural. Others vehemently oppose it, however, since they claim that it will only open up a worse form of discrimination. Those who oppose same-sex relationships may be able to alter their children's genetic makeup if it is revealed they have a homosexual predisposition. In a recent international study, however, a single genetic marker for homosexuality now seems rather unlikely. What seems more likely, however, is partial polygenic predisposition in conjunction with environmental factors. As with most genetic conditions, a cut and clear SNP, indel, etc are usually not responsible for an entire phenotype, but rather a group of genes working together for that expression. While this polygenic expression of phenotype allows for more diversity, it of course results in a much more difficult time deciphering the genetic origins of human and animal behavior.

Phytophagy is the act of consuming plants. This can be done in many ways and evidence of this is all around us. Right here on campus at the University of Massachusetts Amherst, phytophagy is present in the form of insects consuming leaves. On a warm sunny day in fall around 4:00pm on a Friday I left the BCRC room in Morrill Science Center III south by taking a right down the hallway. At the end of the hallway I took a left and then entered a large door into a stair well. Through the big heavy door, there is the stair well that has the walls painted with various themes of science. I began descending the stairs. I walked to the very bottom of the stair well and opened the door to a new hallway where I took a left. I went through a set of doors, down a short set of stairs and through the last set of doors finally stepping outside. I walked down the side walk to the left. I saw a small set of stairs on my right about 40 feet from the door I just exited; leading me to a crosswalk at the bottom. I then went down those stairs. I crossed the crosswalk located at the bottom of the stairs. I was sure to look both ways before crossing the street and made sure no cars where coming. Once across the street I walked across the east lawn heading in the direction of the library tower. At the edge of the campus pond there are two granite benches. The bench on the left is located between two trees. The tree on the right in-between the two benches has a small shoot growing from the base of the adult tree. This shoot is located on the side of the tree closest to the Morrill Science Center buildings. Halfway up this shoot is a leaf that has three large wholes in the center of the leaf almost in a clover shape. It also has two smaller holes towards the apex of the leaf one on each side of the main venation of the leaf. On the left side of the leaf there is a series of holes in what looks like a “cancer ribbon” shape. In my left hand I held the leaf and a ruler on the inches side to show that the leaf is approximately 2 inches long which is approximately 5 centimeters. I held the leaf and measured it with the stem to the left and the apex to the right. I took the picture with my phone.

At the Salk Institute for Biological Studies in La Jolla, California, Janelle Ayres and her colleagues’ had many mice that got sick. Ayres and her colleagues had infected mice with Citrobacter rodentium, which in turn inflamed the colons of the mice. Half of the mice lived, and half died. These mice all had an identical lifestyle, they all ate the same and did the same activities during the day. The point of this experiment was to determine what causes genetically identical mice to respond differently to certain pathogens. She realized that the mice that died, did not have sufficient iron. Thus, she decided to treat the living mice (with pathogen C. rodentium) with iron supplements. This was a rather holistic approach, as she did not go in with full war to try to use antibiotics, and drugs that can later develop resistance in the mouse. This approach supplies to the internal system of the mouse, which boosts the immunity of the mouse, rather than targeting the pathogen with an antibiotic. 

The diversity in the field of biology is part of why I am attracted to the subject. Biology encompasses many subdisciplines and can range from macro-scale ecology type studies, to more microscopic studies such as biological cellular mechanisms. Many biology students I've encountered are on the pre-med track, aiming to be doctors and sepcialists after their time at UMass. Other biology majors I've encountered are more interested in conserving the environment, or specializing in certain organisms such as mammals, fish, or birds. An undergraduate degree in biology can open many doors, and combining the degree with research experience in your desired subdiscipline can be very helpful in finding a job right out of school. When i joined the College of Natural Sciences, I was pretty sure I knew what I wanted to do with my biology major, but I also learned a lot about things I never considered I might learn about. My undergraduate experience in biology has been very educational and fulfilling, and has so much value. 

 The Sonoran Desert's location is at latitude 25° to 33° N. Hot deserts contain sparse populations of plants, due to periods of high temperatures and low water availability. This high temperature results in high rates of evapotranspiration levels, which in turn results to very little water available for this biome.  The temperature is a lot higher than the average annual precipitation. This has a large influence on plant forms. Because it is so dry, stem succulents occur in the cacti of these desert plants. Plants with succulent stems can store water in their stems so they are not left dry during dry seasons. Cactuses are the main desert plants. Cactuses can absorb a large amount of water, which is beneficial as this desert has a higher annual precipitation than most hot deserts. Most the flowers located in this desert also depend on rainfall so they can flower, and for a hot desert, this has a high amount of annual precipitations, so vegetation numbers must be high

As a species, humans have recently become vunerable to allergies.  Even if your parents are asked, they will say allergies were not as much of a concern as they were not.  One theory explaining the prevelence of allergies in humans, particularly those of first world countries involves helminth infections.  When an antigen enters the human body, the antigen bind to T cells which then stimulate B cells.  B cells differentiate to form antibodies like IGF which binds to other cells of the immune system and arm them against the antigen.  IGF is an important form of antibody because it is key to the fighting of helminth infections.  The armed cell can then react to antigens like cats and dust that do not pose of risk to the health of the individual.  In populations with high levels of helminth infections, the IGE levels are very high compared to populations lacking helminth infections and none of the individuals have allergies.  It is thought that the helminth infections keep the IGE "busy" so it does not have time to react to antigens that are not dangerous (those causign allergic reactions).

Plant pathology differs greatly from animal pathology. First and foremost, animals have an adaptive immune system that allows them to generate defences as new infections arise, but plants lack this capacity. Plants have a fixed immune system that either confers them resistance to a pathogen or doesn’t. Plant pathogens come in three general classes, necrotrophs, biotrophs, and hemibiotrophs. Necrotrophs are organisms that simply kill plant tissue upon infection using cellulase and hemicellulase, they tend to be generalists that can infect many plants. For biotrophs to go through their reproductive cycle they require live plant tissue and thus tend to infect specific hosts. Biotrophs will cause slowed senescence and will hijack plant cell machinery to generate metabolites for themselves rather than the plant. Lastly, hemibiotrophs are a mix between necrotrophs and biotrophs. In the first stage of their life cycle hemibiotrophs will act like biotrophs, hijacking plant tissue for their own purposes. In the second stage of their life cycle they will act as necrotrophs and kill the plant. Pathogens utilize three main ways of egress into a plant. They can either directly penetrate the plant through the use of a pilus or penetration cap, enter through pre-existing openings such as stomata, or enter through wounds. Plants have a series of defencive strategies to resist and counter infection. The first line of defence is physical, plants have a waxy cuticle and cell walls that aim to prevent direct access to plant cells. The second line of defence is specific, and is known as resistance (R) gene immunity that follows a gene for gene model. Pathogens produce effectors that aim to mask their presence, and plants produce proteins that are able to detect effectors. If a plant can produce a detector that recognizes even a single effector in a pathogen then it can defend against it, otherwise the plant will be infected. The methods of defence include production of toxins that kill the pathogen, synthesis of papillae to reinforce the cell wall, and a hypersensitive response that involves rapid cell death around the area of infection.

I have chosen Spanish bullfighting as my public event and it shares many similarities and differences with the death pits of Ur. Both are spectacles set before a public audience to show might. They are both considered the heritage of their civilization, that is, they are a part of the culture. Also, they both happen to revolve around cruelty of some kind. It’s interesting how both events are separated by so much time, yet some form of cruelty remains present. Maybe our interest in violence could be understood better by studying ancient civilization? Although they share some similarities, there are plenty of differences as well. The royal graves were the result of human sacrifice, which does not happen in Spanish bullfighting (however sacrifice of some kind does). Also, Spanish bullfighting is a spectacle not meant to incite fear anymore. It’s a public event enjoyed by the masses, who willingly attend. This is opposed to the death pits as those were made to inspire terror in anyone who saw it.

    As I previously mentioned the death pits of Ur were made to terrorize the commoners. This way the elites in power could demonstrate their might and keep everyone in check. There was no overthrowing the government if they could kill all the people in the death pits. It's no wonder the elites enacted such an event as the motive was very strong. Keep themselves in power by squashing any sign of a rebellious hope. Now with bullfighting, the intentions are slightly different. The public event is not meant to insight terror, rather provide entertainment. And it is continued to be enacted because if a politician were to deny it, public backlash may remove them from power. Therefore politicians must also carry out this ritual in order to stay in power, however, the severity of the event is arguably lesser than Urs’.

One topic of life science I’d like to explore is the human eye. Light has both wave and particle-like properties. When resistance (a resistor) is placed against the electrical current, the resistance heats up and glows, converting electrical energy into light energy. The light energy then radiates photons towards the human eye, where it is reflected onto a focal point. This energy then radiates down a signal pathway consisting of neurons. Simply put, the brain creates an image based on the pattern of lights we are receiving, allowing us to see. The most fortunate thing that I believe people take for granted is the ability to see. Eye disease symptoms include hazy vision, eye pain, light sensitivity, and seeing flashes of light at a young age. It is not uncommon to see adolescents wear glasses in today’s age. One research that has been pointing to this is the dangers of blue light reflecting off screens. Short-wave blue light with a wavelength between 415 nm and 455 nm is closely related to eye light damage. Visible blue light is already between 490 and 450nm. The human eye creates a picture that may last a second, but the mistreatment of our eyes will last for a lifetime because our bodies do not reproduce eye cells.