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.

Signs of Aging, Even in the Embryo

I read the article, “Signs of Aging, Even in the Embryo”. In 1961 biologists, Leonard Hayflick and Paul Moorehead discovered that old age is built into our cells. This discovery contradicted the previous common belief that a healthy human cell would multiply forever. This article explains a recent validation to this previous discovery. Dr. Hayflick and Dr. Moorehead reared fetal human cells and found that begging at the fetal stage, cells stop growing in the human body. Cells that stop growing this way came to be known as senescent. The article states, “Given all this research, the last place you would expect to find senescent cells would be at the very start of life. But now three teams of scientists are reporting doing just that. For the first time, they have found senescent cells in embryos, and they have offered evidence that senescence is crucial to proper development.” Essentially they discovered that for life to get off on a good start, you need a splash of old age (senescent cells). Biologists also discovered that senescent cells are important to life for other reasons. They found that, “Besides stopping their growth, scientists found, senescent cells also secrete a cocktail of chemicals. The chemicals they release can create chronic inflammation. They also attract certain immune cells, which seek out the senescent cells and kill them.” This behavior is good for our health because it keeps cells from becoming cancerous by stopping the cells from uncontrollable division. Moreover, the biologists found that senescent cells are crucial for embryonic development because the chemicals they release act as signals for cells to develop into different tissues, to create a complete and functional body.

The material covered in this article affects humanity greatly. The discovery of the benefits of these senescent cells may be able to help find a cure to cancer. If scientists study the behavior of these cells they may be on a track towards a cure to cancer and therefore many lives all over the world could be saved. Also, this article relates to our bio class. We are currently learning about reproduction and embryonic development so this article directly correlates. It is interesting to learn a little bit more about embryonic development from this article, because they would not be something that would be covered in class. However, it is very interesting.

Overall, I found this article to be very interesting. I enjoyed learning about these cells because I had not heard about them before. Previously I had thought cells would always keep growing and multiplying, so I was very intrigued to read more about these cells that stop growing. Although this article was interesting, I think it would have been more interesting if it covered more about the negative affects of these cells rather than mostly positive. Also, the article wasn't very clear at points which made it difficult to understand.

http://www.nytimes.com/2013/11/21/science/signs-of-aging-even-in-the-embryo.html?ref=science&_r=0

"Coldblooded Does Not Mean Stupid"

In the article, “Coldblooded Does Not Mean Stupid,” by Emily Anthes from the New York Times, the preconceived notions that coldblooded reptiles were not nearly as intelligent as mammals was addressed and argued to be wrong. Although species like lizards, turtles, and snakes have been understudied while other species have had a plethora of research released on them, recently scientists have revisited these deserving animals. Originally thought of to be very simple minded animals with very little intellectual knowledge, new studies have been released saying that they are not as primitive as many had thought. These new ideas connect to cognitive evolution, and because retiles, birds, and mammals all came from a common ancestor, the sophistication of that ancestor is can now be thought to be greater. In a variety of experiments performed on different reptiles surrounding their willingness to respond to environmental problems and problem solve reflect the new possibility of their more complex mind. Although the experiments performed were relatively simple, they had previously been overlooked, because the tests done were the same that were done on mammals, and scientists were not taking into consideration, and “scientists commonly [used] “aversive stimuli,” such as loud sounds and bright lights, to shape rodent behavior. But reptiles respond to many of these stimuli by freezing, thereby not performing.” However, now that researchers have learned what type of work needs to be done with reptiles, new advances can be made in this field. 

Studies around cognitive evolution, or the way in which species come about solving problems, is very important to our understanding of ourselves and how we have come to the mental state in which we are today. Knowing that our distant ancestors were more advanced than we previously thought could possibly change our notions around our own and other species’ evolutions. This new discovery could also cause scientists to question how what notions other experiments were performed under, and if they need to be redone from a less biased point of view. 

I thought that this article was written very well. The author incorporated different stories and examples that tied the whole piece together, but did not let that take away from the facts she was presenting. However, I wish that Anthes would have put into context some of the estimated times of evolution, so the effect of this new revelation was more tangible. Still, the article was a great read and extremely informative. 

Citation: Anthes, Emily. "Coldblooded Does Not Mean Stupid." New York Times. 18 Nov. 2013. Web. 21 Nov. 2013.

I read Wolf to Dog: Scientists Agree on How, but Not Where by Carl Zimmer. In the article, the author discussed the confusion scientists had and still have on the location where dogs developed from wolves. Scientists know that dogs developed from wolves because their genes are the most closely related. Originally, scientists believed that dogs developed in South China because Chinese dogs have the closet DNA to wolves. But, this would mean that dogs developed over 30,000 years ago, which some scientists very much disagree on. New studies have shown that dogs may have been bred in Western Europe due to new gene extraction from fossils. This article does not conclude where dogs were developed, but it does not give insight to the possible places where wolves were domesticated leading to new dog breeds.

            This article is important to the real world because of the resources being discovered to find the answer to this long debated question. Scientists have found a way to take fossils of ancient wolves and dogs and replicate those genes into actual gene strands. This will also have the future to possibility study other ancient bones to find how species evolved over time.

            I thought the author only did an ok job in writing his article. I was very confused when I first read it, and had to read it several times to wrap my head around the fact that there was no concluding answer. I thought the author could have made it clearer that there is no answer to this ambiguous question. And he should have specified the different sides more clearly.

Zimmer, Carl. "Wolf to Dog: Scientists Agree on How, but Not Where." New York Times. New York Times,      14 Nov. 2013. Web. 22 Nov. 2013. <http://www.nytimes.com/2013/11/14/science/wolf-to-dog-scientists-agree-on-how-but-not-where.html?ref=science>.

I read the article “An Icy Observatory Detects Neutrinos From Far, Far Away” by Kenneth Chang. This ‘Icy Observatory’ refers to the observatory that was established in 2010 called IceCube Neutrino Observatory whose purpose was to look for and discover neutrinos. Neutrinos are extremely small sub atomic particles which can pass through anything with mass with relative ease. The last report of neutrinos was 1987 which came from a supernova explosion 165,000 light-years away. The IceCube has been established with more than 5000 sensors. These sensors were frozen across a cubic kilometer (about one quarter cubic mile). Their purpose is to look for flashes of blue light which “are given off by the cascades of debris generated by a neutrino.” Neutrinos are hard to detect because they rarely interact and affect the universe. For example every second trillions of neutrinos pass through every person on Earth. Neutrinos are discovered once in a while when a neutrino does collide with something, setting off a cascade of electrons and other subatomic debris. Some scientists believe that some of the neutrinos might be coming from our own galaxy not just from solar systems far away.

This discovery of new neutrinos is important for astronomers. Francis Halzen, a physics professor at the University of Wisconsin who is the lead investigator for the project said, “This gives us a new way to do astronomy.” The high energy neutrinos will allow astronomers to observe the universe through a new spectrum. Before observations were made by gathering photos, particles of light, visible light, and X-rays and Gamma rays. Another supernova like the one in 1987 would drastically help the understanding of neutrinos due to the vast amount that are released after a cosmic explosion.

Overall this was a well written article. The article was at time difficult to understand and I had to do some more research on neutrinos to completely understand what the article was talking about. However the author was able to simplify some aspects which greatly helped in understanding this topic of these subatomic particles. I enjoyed reading and learning about neutrinos and hope they lead to more understanding about the universe in the future. 
http://www.nytimes.com/2013/11/22/science/space/icy-observatory-detects-neutrinos-from-outside-our-solar-system.html?ref=science&_r=0

Signs of Aging, Even in the Embryo

            I found this article to be very interesting.  The article proposed that cells of animals are capable of reaching old age even at the very beginning.  Scientists believed that if human cells were put in a test tube with a good amount of nutrients, the cells would multiply forever.  However, Dr. Hayflick and Dr. Moorehead discovered that this is not the case through their study of fetal human cells.  The doctors found that the fetal cells would divide up to 50 times and then stop.  Cells that stop growth in such a manner are called senescent.  Senescent cells are responsible for several aspects of old age, including wrinkled skin, cataracts, and arthritic joints.  The reason why the cells eventually stop dividing is that the DNA gradually accumulates damage, and switches on a set of genes that cease all growth once the DNA becomes too damaged.  Such senescent cells were found in embryos of mice, which is interesting because “the discoveries raise the prospect that the dawn and dusk of life are intimately connected.”

            This discovery is significant because senescent cells could lead to a cure for cancer in the future.  Cells are more likely to divide uncontrollably and develop into cancer as their DNA becomes more damaged.  However, senescent cells prevent themselves from becoming cancerous “by stopping their own growth and by inviting immune cells to kill them.”  At the same time, an accumulating supply of senescent cells can lead to chronic inflammation that can cause damage to surrounding tissue and harm our health.

            I thought that the article included all the important information about the subject matter, but the information was not presented in a clear and concise manner.  The points made in the article were disorganized and out of order, and I felt that the article skipped around, making it a bit confusing.  The article started out by talking about the discovery of the senescent cells, jumped to their significance, and then went back to explaining how the cells were discovered.  I think the article would have been much more effective if the author finished each point before moving onto the next thing.  Another thing that I did not like about the article is that it was supposed to be about the significance of the senescent cells found in embryos, but the article mainly focused on the general topic of senescent cells found elsewhere in the body.  However, I did learn a lot from reading this article, and the information in the article is relevant to what we are currently learning in class.

http://www.nytimes.com/2013/11/21/science/signs-of-aging-even-in-the-embryo.html?ref=science&_r=0

Zimmer, Carl. "Signs of Aging, Even in the Embryo." Nytimes.com. The New York Times, 21 Nov. 2013. Web. 22 Nov. 2013.

Signs of Aging, Even in the Embryo

Carl Zimmer’s article in the New York Times titled, Signs of Aging, Even in the Embryo, is an intriguing article that summarizes the findings a recent experiment. These recent discoveries have to do with certain cells called senescent cells which are characterized by the stopping of growth after dividing around 50 times. The experiment has discovered that, “senescent cells are involved in many of the ravages of the old age.” This basically means that senescent cells are the cells in our body that cause us to age and grow old. This research has also uncovered that senescent cells are actually found in embryos and may be crucial to proper development. This has raised the very thought provoking question about how “the dawn and dusk of life are intimately connected.” Surely this will lead to further research of senescent cells and it truly brings on a lot of questions about the essence of the cycle of life.

            This article affects humanity as a whole in big ways. First off, this sparks questions about what it means to grow old and what is really happening inside of our bodies. This discovery will lead to dramatic investigations on the true purpose of senescent cells and their function in the human body. In theory, removing senescent cells sounds like a good way to prevent aging; however, this is not the case as senescent cells have multiple key functions in the body such as preventing cancer and ensuring proper development of the embryo. All these questions are vastly interesting and hopefully, more research is done soon.

            I really enjoyed this article for a variety of reasons; one being that we are studying embryos and the development of life in Biology at the moment and I thought that this was a perfect article to review. Additionally, I am vastly interested in the purpose and cycle of life and I am interested to see how this will change the way we look at “growing old”. Maybe some day, we will harness the senescent cells and develop a line to immortality. Only time will tell.

http://www.nytimes.com/2013/11/21/science/signs-of-aging-even-in-the-embryo.html?ref=science&_r=0