AP Biology Cell Energetics Projects

Students in the AP Biology course were given the task of creating a poster, powerpoint presentation and or ANY other form they wished to use to explain a metabolic pathway of Cell Respiration and/or Photosynthesis.

I read the article; Men Can be Such Worms (and Vice Versa) by Douglas Quenqua. This article discusses the developing theory that male roundworms secrete signaling molecules that have the ability to shorten a non-male roundworm’s lifespan. They use the term non-male because studies have shown that these signaling molecules affect both female and hermaphrodite roundworms. Researchers have found that non-male roundworms that are in contact with their male counterparts have a 20% shorter lifespan. However, researchers do not definitively know when the roundworms secrete the signaling molecules, but they have reason to believe that this secretion occurs after sexual intercourse, or copulation. They believe that there are evolutionary benefits to the roundworms’ secretion. They see the secretion’s ability to shorten a non-male roundworm’s life after copulation, as a way is to preserve resources for the offspring and to diminish the mating selection for other males.

This scientific finding is very insightful as it supports the evolutionary theory proposed by Charles Darwin. By lessening the female roundworms’ lifespan, male roundworm secretion increases the natural selection, as only the most fit will be able to reproduce with the depleting number of females. We are also able to see the tremendous affect that male have over the non-male, and that the female roundworms’ main objective is to reproduce. However, this information doesn’t scientifically relate to humans as researchers believe that  “such behavior is unlikely to extend to mammals, [because] they rely on the mother to care for the offspring.”

I found this article to be extremely interesting. I like that it was short and to the point. However, I thought the author should have explained what “copulation” was because I found myself searching for the definition. I would have also liked to see some actual data from their research as it would give more credibility to the article. Overall, I thought the author did a good job explaining his topic and I think I have an adequate understanding of the topic.

http://www.nytimes.com/2013/12/03/science/men-can-be-such-worms-and-vice-versa.html?_r=0 

            I read the article Learning to Diffuse the Aorta by Gina Kolata. It focused on a disease called Marfan syndrome, which causes the aorta to swell like a balloon and burst or tear, causing an aortic aneurism and death. The disease is usually most prevalent in young children because they do not live long past childhood, and it the kids are usually “Very tall and thin, with long arms, legs and fingers. They often had unusually flexible joints, flat feet and teeth that were crowded in their mouth.” The article focused on a recent discovery that could help slow down aortic growth and help people with Marfan to survive. They discovered that they had been mistaken in what they thought was the cause of the syndrome, and that it was in fact a mutation in fibrillin-1, a protein in connective tissue. In someone with Marfan “the fibrillin-1 is defective, and the process goes awry. Instead of attaching to the connective tissue, T.G.F.-beta drifts away from it. Floating free in the bloodstream, it makes cells behave abnormally, leading to many of the problems caused by Marfan, including excessive growth of the aorta.” After discovering what the problem was, scientists discovered that a widely used blood pressure drug called losartan could help to prevent aortic growth. After several years of trials, it has been confirmed that losartan is an effective treatment for people with Marfan.

            I found this article very interesting, but I thought it was a little bit too long and complicated. There was some unnecessary information that would have made the article easier to read and understand if it had been left out. It was a somewhat repetitive in certain areas, and I felt like I was reading nearly the same sentence, only changed slightly. However, I thought the author did a good job explaining the disorder and the treatment in depth, and after reading it I feel like I have a good understanding of the topic.

            I thought that this article related to our study of genetics, because people with Marfin have a defective gene that causes a protein to malfunction. It is appropriate to what we are learning in class. In addition, my mom had an aortic aneurism two years ago that she had surgery to prevent. Like many people with Marfan, she didn’t know she had it and was very lucky to be recommended to see a cardiologist by a friend. When she was operated on, the surgeon said that her aorta had already begun to rupture and that she only had a few more days to live. Fortunately, she was okay, and now with the discovery that losartan can help stop the aorta from growing, many more lives will be saved.

http://www.nytimes.com/2013/12/03/science/learning-to-defuse-the-aorta.html?ref=science&_r=0

Review of: http://www.nytimes.com/2013/12/05/science/at-400000-years-oldest-human-dna-yet-found-raises-new-mysteries.html?ref=science&_r=0

This article discusses a certain fossil, a thigh bone found in Spain, that had previously seemed to many experts to belong to predecessor to Neanderthals. But, its DNA most closely resembles DNA from an enigmatic lineage of humans known as Denisovans. Until now, Denisovans were known only from DNA retrieved from 80,000-year-old remains in Siberia (4,000 miles east of where the new DNA was found). The new finding does not match the picture of human evolution that has been emerging in recent years based on fossils and ancient DNA. Denisovans were believed to be limited to East Asia, and they were not thought to look so Neanderthal-like. The finding shocked the scientists, who are now rethinking human evolution over the past few hundred thousand years. For example, they are now considering that there are many extinct human populations that scientists have yet to discover. It is possible that the newly discovered DNA was passed to both Neanderthals and Denisovans, but eventually disappeared from Neanderthals, replaced by other variants. The article quotes Beth Shapiro, an expert on ancient DNA, who suggests an even more radical possibility: “that the humans of Sima de los Huesos belong to yet another branch of humans. They might have been a species called Homo erectus, which originated about 1.8 million years ago and became extinct within the last few hundred thousand years.”

This article affects humanity because it pertains to our species in particular. Moreover, it is questioning all we have thought about our origins as a species. The study of human evolution is important to our understanding of our own biology as humans and this new mystery could eventually lead to a better understanding of our evolution. This thigh bone will mean even more to humanity once the scientists get more DNA from the Spanish fossil, as well as other fossils from the site, to help solve this new mystery they have just come across. This site, a Spanish cave, proves to be a promising place for new discoveries and new knowledge of our evolution. Since the 1970s, Spanish scientists have brought out a wealth of fossils from the cave dating back hundreds of thousands of years including 28 nearly complete skeletons of humans during three decades of excavations.

The article, although incredibly informative, does at times go off topic. I found this discovery so intriguing so I personally would have preferred to read more about it. Instead, the author talks about various other discoveries which, although interesting, were not necessary for the understanding of the article. Despite some irrelevant information, I thoroughly enjoyed this article and recommend reading it. 

Follow Your Gut Down the Aisle, New Study Says

http://www.sciencedaily.com/releases/2013/11/131128141302.htm

 

Florida State University. "Follow Your Gut Down the Aisle, New Study Says." ScienceDaily. ScienceDaily, 28 Nov. 2013. Web. 28 Nov. 2013.

 

The article, “Follow Your Gut Down the Aisle, New Study Says,” reports that newlyweds should listen to their gut evaluation of their partners when determining whether their marriage will become blissful or miserable. Associate Professor of Psychology, James K. McNulty, and his colleagues studied 135 heterosexual couples who had been married for less than six months. Then, they observed them every six months over a four-year period. McNulty and his colleagues concluded that the emotions that were verbalized by the participants about their marriages do not relate to changes in their marital happiness over time; however, it was the automatic negative evaluations that the partners expressed during the baseline experiment that determined wedded happiness. To begin the experiment, participants were told to inform the researchers of their relationship satisfaction and the severity of their relationship issues. In addition, the researchers told the participants to describe their marriage according to 15 pairs of opposing words, which represent the conscious marriage evaluations made by partners. To receive gut-level evaluations of the marriages, a flashing photo of the individual’s spouse would appear only one-third of a second on a computer screen. Next, a positive word like "awesome" or "terrific" would appear, or a negative word like "awful" or "terrible" would appear. Then, the participants had to press a key on the keyboard to indicate whether the word was positive or negative. In order to measure the reaction time of the participants pressing the key, the researchers of the study used special software. Participants who experienced positive gut-level attitudes were great at processing positive words, and thus, horrible at processing negative words. The opposite was also true with participants who experienced negative gut-level attitudes. Spouses with negative gut feelings had difficulty processing positive words. Even though the experiments were done once during the baseline, the researchers checked in with the couples every six months and asked them to report relationship satisfaction. The researchers found that participants who showed negative automatic feelings reported marital dissatisfaction four years later. On the other hand, conscious attitudes were unrelated to changes in marital satisfaction.

This study, conducted by James K. McNulty and his colleagues, shows that people should listen more to their gut regarding their future marriage happiness. In addition, if people automatically feel that there is a problem present, then they should seek help or possibly end the relationship.

After reading about this study, I believe that much more research must be done in order to conclude whether gut-level feelings determine future wedded happiness. Furthermore, this article leaves out how gut-level responses take place. Therefore, I did some extra research and found out that the intestinal nervous system is wired directly into the prefrontal cortex, the part of the brain that is in charge of the person’s thoughts and decisions, influencing and concentrating on goals. The gut feeling is due to the prefrontal cortex recognizing aspects of situations. Overall, this article was informative and interesting, but it left out important scientific details that the reader should be informed about.

Why Fish Don't Need to Be "Schooled" in Swimming

            I read the article “Why Fish Don’t Need to Be ‘Schooled’ in Swimming” by Jennifer Sargent. It discusses the results of two studies from the publication “Current Biology” on the topic of fish schooling. According to these studies, fish do not learn how to swim in schools; instead, schooling is a behavior that relies on various regions of the fish genome rather than on the influence of other fish. In one of the two new experiments, researchers observed stickleback fish, and after identifying which type was prone to schooling and which type was not, they crossbred the two types. In the end they found that sticklebacks have two genomic regions associated with schooling, one of which also relates to the specialized lateral line that allows fish to sense vibrations in the water so that they can stay in tune with their surroundings. In the second experiment, researchers crossbred surface-dwelling tetra fish with blind cave-dwelling tetra. They found that losing the ability to school and losing eyesight occurred independently of one another, providing “more evidence that schooling behavior is genetic-based and not learned.” The results of these studies have given researchers a lot of new information on the evolution and behavior of fish.

            While it may seem like this topic does not relate to humans, it actually indicates that humans tend to gather in social groups for similar genetic reasons to fish in schools. While the researchers admitted that the second study probably had very little to do with human behavior, the first study relates to human social tendencies. The results show that “complex behaviors associated with other individuals in a very rigid and organized manner can be dissected genetically.” This means that, against popular belief, human behavior may not be too complicated to understand.

            I found this article to be interesting and informative. I liked the way it was broken up into three different sections: an introduction to the topic, a description of the studies, and an analysis of why the findings are important to us. This organization made it easy to understand. It seemed to me like they left out many of the details of how the experiments were carried out, so I may have liked to have some more information. However, some details were probably just left out for the sake of keeping the article a manageable length.

Citation: Sargent, Jennifer. "Why Fish Don't Need to Be "Schooled" in Swimming: Scientific American." Scientific American, 18 Sept. 2013. Web. <http://www.scientificamerican.com/article.cfm?id=why-fish-dont-need-to-be-schooled-in-swimming>.

Summer Reseach Internship Opportunity

The Roswell Park Cancer Institute is offering an interesting program for high school juniors from June 23 to August 8. The program will enable the student to conduct a cancer-related research project under the mentorship of internationally known scientists.

Application deadline is Feb. 3, 2014. Apply on line.