Avery+Saxe+Your+Inner+Fish


 * Your Inner Fish **
 * Neil Shubin **

Excerpt 1: “For billions of years, all life lived only in water. Then, as of about 365 million years ago, creatures also inhabited land. Life in these two environments is radically different. Breathing in water requires very different organs than breathing in air. The same is true for excretion, feeding, and moving about.” (6) This quote talks about how organisms started off in just water and as they evolved, they also started to move onto land. This relates directly to the online activity that we did in class where we determined how each animal was related using a phylogenic tree. In the class example, we saw that there were return trips to and from the sea. This shows how when the creatures started to evolve, they became more adaptable to the environment around them. In the computer program we took the protein sequences of different animals such as the cow, rat, and elephant just to name a few. Once we had these protein sequences, they were placed in the website under the settings of protein, sequence, and FASTA to determine how they relate with the other organisms examined. Once the data for each organism was inputted it could be used with another function on the web site, boxshade, to determine the differences in the protein sequences of each organism. These differences can be used to show how closely related the organisms are because the fewer variances between organisms protein sequences, the closer related the organisms are. The exact distnaces between the unlike amino acids can be found by using the ClustalW_Dist. This function gives you numbers for the distance between each unlike amino acids, and the fewer the distance, the more closely related the organisms are. This is all put together into a phylogenetic tree using the function ClustalW_P. The phylogenetic tree is a tree that shows how closely related each organism is based on evolutionary adaptations. This tree shows what organisms evolved into which, and how they went from the sea to the land and back. In addition to this activity, the quote also describes how there were differences in the ways the land and sea animals breath. This was discussed in class as the fish breath through gills. To do this, the fish must gulp in water through the mouth and have it travel to the gill chambers. These gill chambers “consist of fleshy, sheetlike filaments transected by extensions called lamellae. As water flows across the gills, the oxygen within them diffuses into blood circulating through vessels in the filaments and lamellae. Simultaneously, carbon dioxide in the fish's bloodstream diffuses into the water and is carried out of the body. A fish can close the opercula, or flaps of tissue covering the gill openings, to prevent water from escaping” (2). When the water is flowing over the lamella the capillaries pick up oxygen from the water going over the gills. Since the blood flow in the fish is going in the opposite direction than the water flowing over the lamella, it allows the oxygen to "diffuse from the water into the blood over thre entire length of the capilllary" via a concentration gradient (1). This can be seen in the picture below found on the same website.  This quote also relate to two of the main themes of biology, evolution and science and technology. It relates to evolution because the quote talks specifically about how the animals evolved from just being able to live in the water to being able to live on land. This was done through evolution and adaptations to the organism that would allow it to function in a different environment. As for science and technology, this relates to the quotes because of the activity that we did and how the scientists determined how old the organisms were in the quote. In this quote they mention that the organisms came from 365 million years ago. To find this out there had to have been tests and data run through programs to determine an accurate time frame. This is again similar to the activity that we did in class in that we used a computer program to determine the relative age of organisms. The same thing could have been done to determine that the organisms were 365 million years old. One of these tests is called carbon dating. Carbon dating is radioactive dating on "matter which was once living and presumed to be in equilibrium with the atmosphere, taking in carbon dioxide from the air for photosynthesis" (3). Carbon dating finds the age of organisms by "measuring the radioactive emissions from once-living matter and comparing its activity with the equilibrium level of living things" (3). While carbon dating fins the age of organisms that used to be living, radioactive dating finds the age of radioactive chemicals that are decaying at a constant rate called a half life. The half life is the number of years it takes for that chemical to be decayed. By knowing the rate at which the chemical decays, and the amount of the chemical that remains, one can find out exactly how long this chemical has been around for. I think that this quote is very general and a statement thant most people, even without biology knoledge, would know already. For example, it says that all life orginated in water and then moved to land. I knew this prior to taking any bio classes and would assume that this is common knoledge. Also, the quote talks about how there are different breathing mechanisms needed for organisms on land and in water to breath. This is obvious as the fish have gills and most people should know this. Overall, this quote was very general and i think that many people knew this information prior to reading a book or taking any biology classes. However, this quote can also lead into a much deeper discussion on these topics that would require either research or knoledge from a biology class. Therefore, this quote does a great job of acting as a stepping stone for further conversation on this topic. Works Cited Campbell, Neil A., and Jane B. Reece. //Biology//. San Francisco: Pearson, Benjamin Cummings, 2005. Print. "Howstuffworks." //Howstuffworks "Science"// Web. 26 May 2010. .// "Carbon Dating." Test Page for Apache Installation//. Web. 29 May 2010. .// Pictures from: [] []

Excerpt 2: "During the fateful summer of 2004, Randy was taking these cases and injecting a molecular version of vitamin A into the eggs. After that he would let the eggs develope for several months until they hatched." (44) This quote talks about injecting a molecular version of vitamin A into the eggs. This is similar to what we did in the pGLO lab when we injected Green Fluorescent Protein and ampicillin resistant genes into the bacteria that caused them to glow under the ultraviolet light. This quote is only a general description of the process used to insert the vitamin A into the egg. However, in class we actually inserted the pGLO genes into bacteria. In the lab we put the transformation solution into pipets that were then placed in an ice bath. We then took a colony of bacteriaand put it into the CaCl2 solution and put the pGLO solution in one of the pipets. These pipets were then placed back into an ice bath before being placed in warm water and then back on ice. Then the LB broth was added to the pipets and after being incubated the solutions wee placed on agar plates and incubated again. This procedure allowed us to have a control for the test (-pGLO pipet) while finding out that the transformation of genes was able to occur. A similar procedure to this one would have had to been done in the quote explained in the test in order for the vitamin A to be transferred into the egg. This process is a very important concept because it allows scientists to transfer genes into organisms that can help them strive in life or grow stronger. The quote just mentions the idea, and it relates to the discussions and labs that we did in class on this same topic. The quote also talks about the eggs hatching. This occurs via the process of meiosis and fertilization in humans. In humans the haploid sperm cell fuses with the haploid ovum. The fusion is called fertilization. Prior to the fertilization occuring meiosis occurs where the number of chromosomes is cut in half so that when the gametes fuse during fertilization, the chromosome number will return to its orginal entirety. For a more detailed on this process, you can read post 2 on emma's page. This concept relates to the quote in that the quote talks about the eggs of the chicken developing. Chickens devlope inside an egg where the yolk "is released into the oviduct (a long, spiraling tube in the hen's reproductive system), where it can be fertilized internally (inside the hen) by a sperm" (3). This is similar to fertililaztion that occurs inside a human with the only difference being a yolk is fertilized by a sperm in the ovule whereas in the human body the egg is fertilized by sperm. After the fertilization occurs the yolk continues to develope until it reaches its resting point (being laid and nurtered by th mother hen. The embryo that the egg becomes is then put through a 21 day incubation period. This is similar to the development inside the human body in that in humans, the embryo develops for 9 months. At the end of the chicken eggs' incubation period, the egg hatches and the baby is born, whereas in humans the mother gives birth to the baby. The development of a chicken egg relates to that of the human baby in many ways. The human development was greatly expanded upon in class and emma did a great job of summarizing what we learned. The details in this quote relate to the key concepts of science and society. This is because of the technology that was used to insert the vitamin A into the egg for the testing purposes. The technology that was involved here was first the knowledge of how one can insert a gene, and second is the technology that was used to insert the vitamin A into the gene. The process of transferring chemicals into other organisms is a very important concept that is being used all throughout the world today. Today scientists are inserting genes into corn, cattle, and other animals, fruits, and vegetables. The corn is being genetically modified so that it can grow bigger and in more sections of the world. This will allow for more corn to be grown and to be fed to more people. Also, the larger the corn is, the more money the people can charge for it. Therefore, by genetically modifyig this organism people can sell it for more money and grow more corn than previously possible. The cattle is being modified so that it can be bigger than before with more meat that people like to eat on it. This means that there will be more steaks that can be made from one cattle than before. This again will maximize the profit that can be made form this animal. While there are many upsides to genetically modified organism, by changing the genes in these organisms harm is also being done to the organism and possibly to the people consuming the food. The side efects of eating these modified organisms is unknown and could pose harm to people. Also, the organism that are being modified are becoming sick with diseases that they never had experienced before. This was all addressed in much greater detail in the essays that we wrote in class, but this is a synopsis of this topic and how it relates to the quote and theme of science and technology. I think that this quote is a great topic where the author could have talked about how he injected the vitamin A into the egg. However, the author never did go into any more depth and i think that he missed out on a great spot to educated his audience on how this technology is utilized and the process that is used to perform these scientific feats. I know that because we were in a classroom setting specificlly for biology, that we could go more indepth on this topic and many others, but i think that even a brief overview of the process used would have made this quote and section of the book so much better for the entire audience. As for the eggs development, the same thing happened. This is the only thing that the author talked about in term of depth on this topic. This was another great point where the author could have even just scratched the surface on this topic to inform his readers on a little bit about what was happening in this process. However, he never did this and i think that it takes away from the book a little because this is a book that i look at as being educational and for pleasure, but if the author isn't going to discuss certain topics at all than i believe that it detracts from the value of the book.

Works Cited Campbell, Neil A., and Jane B. Reece. Biology//. San Francisco: Pearson, Benjamin Cummings, 2005. Print. "CELL DIVISION: Meiosis..."// Estrella Mountain Community College//. Web. 01 June 2010. . "Chicken Egg Development - EnchantedLearning.com."// ENCHANTED LEARNING HOME PAGE//. Web. 01 June 2010. .// Picture from: [] Excerpt 3: "If sonic hedgehog hadn't turned on properly during the eighth week of your own development, then you either would have extra fingers or your pinky and thumb would look alike." "We now know that sonic hedgehog is one of dozens of genes that act to sculpt our limbs from shoulder to fingertip by turning on and off at the right time." (53) This quote talks specificlly about the regulatory mechanisms that are involved in the human body. The quote mentions the regulatory mechanisms that turns on the sonic hedgehog gene. In addition to this regulatory mechanism, we learned about a few more in class. One of these regulatory mechanisms is in mismatching repair of DNA. The repair enzymes involved correct errors in base pairing to ensure that all guanines are paired with cytosines and adenines are paired with thymines. The DNA strands can also be damaged by chemicals, radioactive emmission, X-rays, UV light, and certain other molecules. One of these other molecules are the molecules found in cigarette smoke. This is part of the reason why cigaretts are so dangerous to people. A nuclease is in charge of cutting out and replacing the damaged sections of the DNA. This process is called nucleotide excision repair. These regulatory mechanisms are needed so that the DNA can function as it should. If the base pairs are matched up incorrectly, than the protein cannot be correctly coded for. Also, if the DNA is damaged then it could be difficult for it to be translated into mRNA, tRNA, or proteins and amino acids. Besides these regulatory enzymes, there are also portions of the DNA that are called telomers that postpone the erosion of importnat DNA base pairs. The telomers are sections of unimportant or "junk" DNA that are shortened or cut every time the DNA strand replicates. By shortening the telomers instead of the important base pairs of the DNA, it allows for more replications to occur while still having the DNA function normally. The quote talks about what happens if the sonic hedgehog gene doesn't turn on after 8 weeks, in that you will have extra fingers or a pinky and thumb that look alike. Most of the time when there are changes in the body like this it is the cause of a mutation to the dna. There are a few types of mutations that can occur within the body of a human or other organism. These mutations are point mutation, frame shift mutation, deletion, insertion, inversion, or DNA expression mutation. Point mutation is when there is a chage in one "base of the gene sequence" (1). A frame shift mutation is when "one or more bases are inserted or deleted" (1). A frame shift mutation can cause a huge change in the way that the DNA is read because by adding or deleting one base gene, it changes the three base genes that are read at one time to make the corresponding protein. Therefore, a frame shift mutation can complete change the proteins that are resulting from the reading of the DNA sequence. Deletions are when DNA sections are missing. The length of these missing fragments can vary in size from one small section of three genes or a larger section of many genes. Insertion is when extra DNA is added to the original chain which chages the way the sequence is read. Inversion is when "an entire section of DNA is reversed. A small inversion may involve only a few bases within a gene, while longer inversions involve large regions of a chromosome containing several genes" (1). Finally, DNA expression mutation is when "there are many types of mutations that change not the protein itself but where and how much of a protein is made" (1). This means that there can be too much protein made or the proteins could be made at the wrong time or at the wrong cell type. For a more descriptive analysis of this section read Shivani's post 1. This quote relates to the theme of regulation. This is because the quote talks about how the sonic hedgehog gene is turned on in the eight week. If it isn't turned on then the regulatory mechanisms aren't doing their job. The regulatory mechanisms in the human body had to turn on and make sure that the sonic hedgehog gene is turned on or else the person will have fingers in the wrong place or a pinky and thumb that look alike. This is one of many regulatory proteins that are present in the human body that are all in charge of something different. These regulatory genes ensure that there are no or few mutations that can occur and have the human body work differently than it should. The regualtory enzymes and structure on DNA is talked about in the first paragraph on this post. Regulation is a vital part of the human body because if the regulatory enzymes stop working then there will be mutations in many people and the body wouldn't function as it normally should. I think that this quote is very interesting because it explains how people have extra fingers or fingers that look alike. I think that it was a great explination of this, but i also think that the book could have said a little bit more about the regulatory mechanisms involved so that the reader could learn exactly what is happening in their body. I know that this might be a little complex for all readers to understand, but i think that if you are going to bring up a ppoint like this, then you have to finish explaining why this phenomen occurs.

Works Cited Campbell, Neil A., and Jane B. Reece. Biology. San Francisco: Pearson, Benjamin Cummings, 2005. Print. Toland, Amanda Ewart. Untitled Document//. Web. 05 June 2010. .//

Excerpt 4: "Our skin is smooth because cells can communicate to maintain its integrity and the regulatory of its surface. Until something out of the ordinary happens, like, for instance, we get a wart. The cells inside the wart aren't following the rules: they do not know when to stop growing" (118). The first part of the quote talks about how the cells can communicate with each other. This relates to our class discussions and learning about cell communication. Cells can communicate in multiple ways. One such way is via cell-cell communication. This occurs when one cell interacts with cell receptor proteins in a neighboring cell. This means that the cells must come in contact with each other. Only when this connection occurs, and both signaling and receptor molecules are present on cell surfaces, can the communication and transformation of information begin. "This type of signaling is known as juxtacrine signaling" (1). Another type of signaling, called paracrine, is when the signal is "released from one cell and travels only a limited distance" to another cell (1). When the signal reaches its destination cell, it interacts with receptors "located in cells within a local neighborhood" (1). The third type of cell communication is when the cell releases its signal into the bloodstream, which can move throughout the body. The signal can react with cells that only have the appropriate receptors. This type of signaling is called endocrine communication. The final communication is between organisms outside of one's body. Exocrine glands secrete materials into the world outside the body of the organism. These materials are involved in interactions between organisms where they can transfer information between organisms. "When a signal molecule binds to its receptor it alters the receptor's 'activity' " (1). This alternation of the receptors activity can be the way that the cell receptors interact with other proteins or its enzymatic activity. These changes in the "receptor activity can, in turn, alter the activity of 'down-stream' proteins, often leading to changes in which genes are 'expressed' -- that is, which genes are being used in the cell" (1). These changes with the proteins and gene expression will also change the way the cell behaves. It is vital for cells to communicate with each other, and this quote briefly talks about this communication. We learned about it more in class, and it clearly related to this quote. In addition to talking about cell communication, the second portion of this quote talks about how a wart or other infection doesn't know when to stop growing. This wart or infection is a type of virus. Viruses cannot reproduce by themselves. Therefore, they require a host cell, where they attach themselves to the cell membrane of the specific animal cell or cell wall of the specific plant cell that the virus wishes to invade. Once the virus attaches to the cell membrane or wall, it can inject its "DNA into the cells of the host organism" (2). This occurs via the use of a "hollow tube structure to puncture the cell wall/membrane and pass its DNA into the cell" (2). The new virus cells are then incubated and allowed to grow inside the invaded cell. The virus DNA then reproduces inside the cell and can leave via the process of osmosis. These new virus cells then attach to other cells inside the body and infect them too. There is also another way that a virus can reproduce, which is where the virus implants its DNA into the host cell where it reproduces or can lay dormant. If the DNA lays dormant, than it will be similar to that of HIV and AIDS. The viruses DNA reproduces when the host cell reproduces to continue to carry the viruses DNA. The virus will continue to reproduce in this manner until "stopped by the host's immune system or until the host dies" (3). This quote relates to the theme of the relationship of structure to function. This theme relates to the quote because it talks about how the cells communicate with each other. During this communication process, the receptor regions accept signals from the appropriate shape. When the signal molecule alters the shape of the receptor region, it changes what signals the cell can accept. This changes the information that the cell can obtain. The change in shape also changes the way that the cell can interact with proteins or enzymes. This change in interaction can affect the way that the genes are expressed. By changing the way that the genes are expressed, it will also change the way that the cell behaves. If the cells behavior changes, then it could alter the way that it is used in the body of organisms. This shows how this quote relates to the main theme of structure and function. I think that this is a very interesting quote and it brings up a very important aspect of biology. I like the way that the author addressed both topics, by giving an example of each. Even though he didn't describe what cell communication was or how it was done, he still gave an example so his readers could connect to what he was writing about. In addition to this, i think that the author did a very good job of connecting these topics to the story and the way he was addressing the topic of how a fish transformed into a human. This is important because while it is a good quote and important concept, it didn't change the way the book was told, and i think it even enhanced the telling of this story.

Works Cited "Cell Communication." MadSciNet: The 24-hour Exploding Laboratory. //Web. 08 June 2010. . Sherwood, Chris. "How Do Viruses Reproduce? | EHow.com."// EHow | How To Do Just About Everything! | How To Videos & Articles//. Web. 08 June 2010. . "Viruses."// Oracle ThinkQuest Library//. Web. 08 June 2010. .//

Excerpt 5 "What really gives cartilage its pliancy is another kind of molecule, one of the most extraordinary in the entire body. This kind of molecule, called a proteoglycan complex, gives cartilage strength when squeezed or compressed." (126) "A proteoglycan, then, is a molecule that actually swells up with water, filling up until it's like a giant piece of Jell-O." (126-127) The first part of the quote talks about the cartilage in the human body. It mentions that the cartilage has the ability to squeeze or compress, and it has strength when this occurs. Cartilage is a “specialized form of connective tissue containing chondrocytes which secrete, and are surrounded by, an extensive intercellular matrix. Chondrocytes occur singly or in isogenous groups, composed of 2-8 cells derived by mitosis from a single chondrocyte” (1). These cells are found in the cavities or lacunae of the matrix. This matrix zone is located next to the “lacunae and the dark staining zone is called the capsule” (1). Cartillage gets its strength and durability from the matrix that the cells reside in. This matrix is a “interlaced network of collagenous and/or elastic fibers in a ground substance, a gel of complex proteoglycans” (1). There are three different types of cartilage that are varied by the characteristics of the inner matrix. The first type is “Hyaline cartilage is found lining articular surfaces, and in the nasal septum, tracheal rings, costal cartilages, and the epiphyseal cartilage of growing bone” (1). “The cartilage matrix contains collagen fibers, but these are very difficult or impossible to see” (1). The elastic cartilage is located in the “ear and epiglottis, where it provides a rigid but elastic, framework” (1). The main components of this type of cartilage is “elastic fibers but type II collagen is also present” (1). Some of these elastic fibers can also be seen in the “tracheal cartilage” (1). The third and final type of cartilage is the fibrocartilage which can be seen in “intervertebral discs, the pubic symphysis, in menisci of joints, and often occurs where tendon and ligament are joined to bones. It resembles a dense C.T. which contains islands of chondrocytes embedded in cartilage matrix. Its appearance varies with its location. The major and characteristic intercellular component of this tissue consists of thick, interlaced collagenous fibers. The ground substance is much less abundant than in hyaline cartilage due to the preponderance of fibers” (1). The function of cartilage in the body is to support the joints and bones. In addition to this, the cartilage connects the joints and bones to each other. Cartilage is very tough and flexible tissue that is a crucial part to the human body. The second part of this quote relates to the osmosis and diffusion lab that we did in class. In this lab a dialysis bag was used as a semi permeable membrane that would allow the materials to diffuse through the surface. This bag was filled with water and a predetermined amount of sucrose. This bag was then placed in a beaker of just water. After 30 minutes the bag was dried and massed. The changes in mass were recorded and used to determine how the water and sucrose moved between the bag and surrounding water. When the water was moving into the bag, it caused the bag to grow larger or swell to a sense. Similar to the proteoglycan described in the quote, the material swells when taking in water. This is also similar to the way that plant cells respond to absorbing water. As seen in the attached picture, when plant cells absorb water the vacuoles expand to account for all of the water in the cell. The picture shows how the normal plant cell has multiple vacuoles, but when the water comes into the cell the vacuoles turn into ne large vacule to try and contain all of the water. In addition to this, the cell often starts to swell and push on the cell walls.

The picture could not be loaded onto the webpage, but can be found at this website: [] I think that this quote is great at describing how some cells swell when they absorb water. The book does a great job at simplifying this concept that can sometimes be a little difficult to understand. The first part of the quote was also good, but it didn’t address the facts about cartilage as much as it did with the swelling of some cells. Cartilage is a very vital part of the human body, and the book just seems to mention it and doesn’t explain more about this part of the body. I think that overall though the author does a great job throughout the story of describing and addressing many different and important pieces of biology. He simplifies these ideas to an extent that all people can understand. Therefore, this book is great to teach most people of basic knowledge level about the core ideas behind biology. While the classroom situation does a good job of going more in depth on these topics, this book is good for a refresher on all of these topics and being able to briefly show people what is occurring around them.

Works Cited Campbell, Neil A., and Jane B. Reece. Biology//. San Francisco: Pearson, Benjamin Cummings, 2005. Print. "Cartilage."// Office of Educational Computing & Technology//. Web. 12 June 2010. .

Comment Number 1 on Phil Schichman Post 1 I really like how you made the connections from the quote to the themes of biology. However, i think that you could have added on to the description of evolution to talk about some of the activities we did in class. For example, i talked about the online activity that we did where just by examining the proein sequences of different organisms, the computer program was able to produce a phylogenetic tree. This tree showed how the creatures evolved from one another over time and how they went from living in water to being able to live on land. This is a big part of the book in that the scientists are trying to examine the fish to determine how they went from looking like a fish into looking like a human. I think that this online activity was very good at showing how the protein sequences in organisms can be used to determine how they evolved over time. This shows just how much technology can influence the way biologists examine data and search for answers now. Another activity that was good at showing evolution was the animal diversity lab. In this lab we dissected 13 organisms to look at the physical features that were present. We were looking for features such as jointed appendages and vertabrae in the more complex organisms, and tissue layers and diggestive systems in less complex organisms. This was important because the organisms that had the jointed appendages and or veratbrae probably evolved from the more simplistic creatures that only had tissue layers and digestive systems. The features that each creature had helped to make a phylogenetic tree of our own. In addition to teh physical features, we also looked at the phylum that each creature was in. This allowed us to follow a sample tree to have an idea of where the creatures noramlly are on a tree. However, by also taking into account the variance in features that resulted from evolution into more complex organisms, it becomes possible to map out the evolution that occured. The phylogenetic trees allowed us to show how we thought the organisms looked at evolved into what they are today. The following web site does a great job in explaining what a phylogenetic tree is, and gives examples of trees for certain organisms.[] I like the connection that you made to the different time periods. I think that the chart you had really helped to explain this concept to everyone. However, i woould have also talked about the video that we watched in class about this. The video did a good job of showing some of the time periods and what animals were present in these periods, as well as how they evolved over time to be able to strive and survive with the creatures that were also living in that period. We also wrote down these time periods and animals present and evolutionary changes present in the video, so i think that refrencing that would allow us to remember a little better what you are talking about. The video however was just a brief overview and you did a great job of going much more in depth on all of the time periods covered and even added a few more. The only different view that i have from you is when you talk about it being impossible to find a column of sedimentary rock that would revel the history of life. While i do agree with you that it would be extremely unlikely to find one column that revels all of the answers, but i think that it is possible to find two or three columns that can do this. This is because one of the columns could show a step by step evolutionary process of how the fish evolved over time to go from sea to land, and another one or two columns could show how the fish evolved step by step to look more like a human with the physical features we have today. I think that this could be found in the right type of rock that is in an ideal location. For example if the rock was sedementary and by a body of slow moving water where the fish could be kept in the rock as fossils, then i think this would be possible to see the cahnges. Also, this is what the authors of the book are trying to do and they are finding all different kinds of fossils in the United States alone which means that if they went to a spot that was perfect for fish fossil findings, then there is no reason why the scientists couldn't find these answers in two or three columns of rock. Overal i think you did a great job of connecting the quote to the themes of biology and showing and talking about the different time periods in biology that were breifly mentioned in the quote. The only thing that i dind't agree with you on was the idea that it would be impossible to find a column of rock that contained all the answers that were being looked for. Also, i think that if you talked about some of the activities that we did in class we could all relate to your discussion a little bit more. Avery Saxe PS: Sorry for the weird username, i needed something that i would remember and this is my fantasy baseball username so i figured i wouldn't forget it.

Comment number 2 on Lindsey Racz on post three I think that you did a really good job of connecting the quote to the different themes of biology. You also made a really good connection to the real world. You did this by using africa and the south american jungles as examples. I thought that these examples really helped to add on to the connections and helped people understand what you were talking about. I would also talk about how this is a mutual relationship. This is because the chili better is benefiting from not being destroyed from the digestive system of mammals, and it benefits the mammals because they don't have to take the heat from the peppers. By neither one of these being harmed. Therefore, this is a great example of a mutual relationship. In addition to the mutual relationship, the quote also shows a good example of a Commensalism relationship. This is because in a commensalism relationship, one side benefits while the other side is not effected. This is described in the quote when it talks about the birds dispirsing the seeds over a large area of land. The birds in this example are unharmed, whereas the seeds are benefiting. The seeds and pepper benefit because they are being spread and able to reproduce with other seeds in a larger area of land than before. This spread in the dispersal of seeds allows for greater growth of seeds and will benefit the pepper. This quote did a great job of addressing two of the three relationships between organisms as it only left out the Parasitism relationship as it didn't talk about one organism benefiting and the other being hurt. Next, you mentioned how the seeds were dispersed through the air, but in class we also talked about spores being moved through water. This is because the spores are so small that they can float on top of the water. Therefore, when the spores are put into the water, they float down stream until reaching a plant that will take up the spore and use it to reproduce and create a new plant. This is for nonvascular plants, but for vascular plants we talkeb about how it can also be transported by being placed in animal fur. The quote talked about the birds carrying the spores, but the spores can also be carried in the fur of the animals. This is because the spores are lost in the fur and can fall out when they are moving. This brings the spores to new land where it can be fertilized by other plants. I think that the examples you gave for the seed dispersal discussed in the quote was great and really added to the connection. If i had to go against something that you wrote, i would disagree with when you said the kids who didn't llike fruits and vegitables while growing up looked smart. This is because fruits and vegitables are a vital part for thee growth and development of a healthy person. If fruits and vegitables weren't healthy, then why would people sontinue to eat them, and have them advertised as foods to eat to improve the health of people. Even though you talked about one of the examples that cause stomach cancer, that is one example, and shouldn't be used to show that it is unhealthy to eat fruits and vegitables. Avery Saxe

Comment Number 3 on Katie Buyse Post 3 Katie- I really like how you talked about how having continual access to iron can be counterproductive for macrophages as the bacteria can grow off of this. However, I think that it is also import to discuss the immune system and how that relates and how the macrophages are used in this system. In addition, I think that this quote can be connected nicely to the theme of regulation. In the immune system, the invaders are first met by the complement system. This is proteins that are flowing freely in the blood and signal for “trigger inflammation, attract eater cells such as macrophages to the area, coat intruders so that eater cells are more likely to devour them, and kill intruders” (1). The phagocytes are then responsible for finding and eating the invaders. Granulocytes attack invaders in large numbers and “"eat" until they die” (1). Puss in an infected wound is dead granulocytes cells. Next are the macrophages which are “slower to respond to invaders than the granulocytes, but they are larger, live longer, and have far greater capacities” (1). The macrophages also alert the rest of the immune system that there are invaders in the body. Finally, the dendritic cells are “"eater" cells and devour intruders, like the granulocytes and the macrophages” (1). In addition to this, these cells aid in the alerting of the body that there are invaders present. Then there are “White blood cells called //lymphocytes// originate in the bone marrow but migrate to parts of the //lymphatic system// such as the lymph nodes, spleen, and thymus” (1). This contains T and B cells. T cells can either be helper or killer cells. Helper T cells are a “major driving force and the main regulators of the immune defense” (1). They activate B cells and killer T cells. The helper T cells are activated by the macrophages. Killer T cells specialize in attacking cells that are infected with a virus or bacteria. The killer T cells have receptors that are used to search each cell to ensure that there are no antigens in the cell and if there are, then the cell will be killed. “B lymphocyte cell searches for antigen matching its receptors” (1). If it finds an antigen, it connects to it and waits for proteins from the helper T cells to become fully activated. The B cells then divide and produce clones of themselves. Then, the plasma cell is specialized in producing antibodies. These antibodies are can only respond to the same antigens that match the B cell receptor. The antibodies are released so that they can go out and find the intruders and kill them. Finally, there are memory cells that are produced by the division of B cells. They are used to remember specific intruders and if it recognizes an intruder, it makes the activation stage much faster than previously accomplished. This fast reaction allows the invaders to be wiped out before the human can feel ay receptors. There are some great pictures of this on this website along with the description of each part of the immune system: [] There is also a good video talking about the macrophages and other parts of the immune system at this link: [] This quote relates to the theme of regulation in that the macrophages are used in regulating the body and what infectious agents can come into the body, as well as the iron that the macrophage and bacteria use. The macrophage regulates and aids in the regulation of the human body. As described above in much greater detail, the macrophages help to eliminate antigens. Macrophages eat and activate other part of the immune system to keep the body safe from intruders. The macrophages eat and kill as many of the antigens that they can, but whatever gets passed them are killed by the responses that are activated by the macrophages. As for the iron, it regulates the isolating of the infectious agent, and how much the antigen can grow. The virus or bacteria needs iron to grow and increase in numbers and size. However, if there is a lack of iron available to it, then the bacteria or virus will have a harder time growing and spreading throughout the body. The macrophages can also isolate the invading organisms if the iron is absent. This helps the body eliminate these infectious agents, so the iron is regulating the way that the body deals with these infectious agents. The iron and macrophages really show the theme of regulation at its best as they both regulate the immune system and help prevent infectious agents from spreading throughout the body. As for something that I disagree with you on, when you say that it is very dangerous for the body not to be able to recognize when there is enough iron present. However, in the next sentence you say that it offers protection from nastier infections and diseases that could be picked up along the way. Well if it is helping the body stay healthy and not get infected from these worse diseases, then why is that a bad thing? I think that while it isn’t great that the body can’t recognize when there is enough iron in the body, I would still rather have that then have some of the nasty dieses that it is preventing. The whole point of the immune system is to protect the body from harmful diseases, and if that is being done, then the job of the immune system is being done. Therefore, it shouldn’t be a crucial problem if the body can’t recognize how much iron is present in the body. Works Cited "The Immune System - in More Detail." //Nobelprize.org//. Web. 13 June 2010. . "YouTube - Macrophages, B-cells, Pathogens, Antibody Immune Response." //YouTube - Broadcast Yourself.// Web. 13 June 2010. .