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.