Since I have been having so much trouble with my Reflections page on ePortfolio, I decided to import everything over here, as I am far more familiar with my own website and its construction. I have imported the previous postings I have made, and hope this works far better than my previous attempts.
This post is related to the Exam One Materials Discussion. For this discussion I asked, “My question relates to one of the points in the exam review materials. It asks to explain what determines protein structure and why protein shape is important. I feel as though I understand that protein structure is determined by the bonds making up the protein, and that its shape helps fulfill the protein's specific role, but I don't know that I have a firm grasp on either of these concepts. My understanding seems to be very surface-level. I'm wondering if someone might have a better way of explaining these concepts. How do you describe these concepts? Am I overthinking this, or is it really as basic as I have described?”.
What I found most confusing is not necessarily the concept in and of itself. My confusion lies in my wondering if I am thinking about this too simply, or if I am missing a tangential concept that might further my knowledge of the issue at hand. I find that having information presented in numerous ways leads to my better understanding of it, as most everyone has their unique way of explaining a concept or idea. When this type of collaboration occurs, I am usually provided with a moment of clarity, where something I have struggled with finally seems less confusing. As of this writing, I have not received a reply to my question, which is understandable, given that I have approached this assignment closer to the deadline than I would have originally hoped.
When I chose a question to respond to, I looked for a question that addressed a point of confusion I had as well. Since we are/were struggling with the same thing, it forced me to analyze deeper where my confusion was arising, so I could attempt to speak intelligently about our shared issue. In doing so, I had one of those moments of clarity I discussed previously, where suddenly, something of which I felt I possessed little understanding became a bit more relatable and comprehensible.
Exam Two Discussion
One of the biggest things I have learned during the period between Exam One and Exam Two is the difficulty I have in absorbing material. This issue seems to be two fold. Firstly, I have always had trouble attempting to learn challenging concepts without having a tactile response. Second, I struggle when I seem to be missing a piece of information, and don’t know the full context of what we are discussing. This was the genesis of the question I asked on our discussion board. I tend to get hung up with what may be considered trivial matters, but that leads me to research further on a topic. Although I may be considering an idea or concept somewhat tangential (like wondering where the CoA comes from to form Acetyl CoA) to the topic at hand, I then expose myself to the subject further, which leads to more understanding of the main point (ie, aerobic respiration and the role of Acetyl CoA in general). Since exam one, I have also learned that coming back to school later in life is much harder than even the first time I came back to school after an extended break. Managing my time means I can’t necessarily delve into the tangential concepts I come across. I need to find additional resources and ways to make things “real”, relative to the main focus of the topic under study. My question regarding the materials for Exam Two was as follows: I have been having a bit of trouble with aerobic respiration. I believe I understand it in broad strokes, but my questions specifically pertains to the formation of Acetyl CoA. I know it is a product of pyruvate oxidation, formed after the dehydrogenation of NAD+ to NADH and the removal of a carboxyl group, which leaves only the acetyl group. My question pertains to from where the coenzyme A comes from to form the Acetyl CoA. Is the coenzyme A complex just waiting around for an acetyl to come along? Is it imported, or is it made as needed? If it is coming from somewhere else, where would that be?
Exam Three Discussion
My Question
When a condition or trait is typically found on the X or Y chromosome, it is called a ________ (sex-linked condition). Only women can be _____ (carriers) of an x-linked disease and will not display traits of the disease if they are _____ (heterozygous). Chromosomal abnormalities can occur through various means, such as ____ (inversion), when a portion of the respective chromosomes is attached upside down in ____ (prophase I). When ______ (duplication) occurs, more than one copy of a gene is found in the same sister chromatid. The failure of homologous chromosomes to separate leads to an incorrect number of chromosomes in ______ (nondisjunction). This failure of separation occurs in either the first or second ______ (anaphase) of meiosis. When _____ (aneuploidy) occurs, a fertilized egg contains the wrong number of chromosomes for that species. Through ____ (deletion), a portion of the chromosome is absent, leading the offspring to be deficient of this genetic material. If there is a switching of pieces of non-homologous chromosomes, ______ (translocation) has occurred, which will have various manifestations depending on their size. Genetic disorders are also caused by mutations, caused by ____ (mutagens), the presence of which increase the chance of these disorders to occur.
The Question I Answered
Thomas Morgan was a man who experimented with fruit flies to study genes/inheritance. While studying genetics he happened to discover something called the Chromosomal Theory of Inheritance. Linkage is having 2 or more genes close together on the same chromosome. During Prophase 1 of meiosis, they will likely move together. Because of this, it becomes a violation of the Principle of Independent Assortment. If these genes stick together, chances are they can be found in gametes and can be passed to offspring. If they are on the same chromosome but far enough a part, they could possibly move independently.
Reflection
The chapter most relevant to my question was chapter 13, in the Open Stax online book. The hardest part I have with the question of genetic disorders is remembering all of the terminology and how it all fits together. It is easy for it to become disjointed as I am reading through it, and the repetition and exposure is probably the most helpful method I have to learning it. Writing my own questions means that I need to have a base level understanding, and the immersion it provides makes things stick in my head better.
To me, the text was more helpful than the Canvas pages. There is significantly more detail in the textbook information, but that gives me a bit greater context. The Canvas pages work quite well for bullet points and the basics, but the extra information helps me process through what is going on in each of the methods of genetic disorders I used for my questions.
I think the most relevant connection I have made through our previous reading probably ties into the idea of mechanization, or order to the way of things. Even though I chose to write about genetic disorders, there are specific, known mechanisms that occur which lead to them. We may not understand why something happens, but we have a term for it, and a method to explain why it happens. I consider these concepts to be similar to how a cell functions. Event A occurs, which leads to Event B, down the line. That could either be the production of ATP, or the inversion of a portion of a chromosome.
Reflection on final exam materials:
Describe how gene flow can act to reduce genetic differences between adjacent populations.
In order to describe why gene flow reduces genetic differences between adjacent populations, I want to first define the basics of the concept. Gene flow pertains to the passing of genetic material from one population to another. Such occurrences happen often in wildlife populations. As an example species, wolf packs display this idea rather clearly. In areas with healthy ecosystems conducive to wolf populations, neighboring packs tend to be related genetically. As wolf packs develop, pups split off from their natal pack, and move throughout the territory, sometimes joining with other packs in the general area, taking their genetic material with them. In a study of Minnesota wolves conducted in 1987, L. David Mech found that an individual male wolf was observed living partially with his natal pack and partially with a neighboring pack, before eventually permanently integrating with the neighboring pack, and mating with a female there. (Wolves, Behavior, Ecology and Conservation, 2003) The pups produced from this mating melds the genes from both packs. The 2003 book only described this one instance, as it was a direct observation of this wolf integrating into a new pack, but it is not improbable that this behavior would have occurred previously between these two packs, and other packs in the region, leading to genes flowing back and forth throughout the packs as individuals dispersed between their respective populations.
Explain what Darwin meant by “descent with modification”
When Darwin was thinking of ways to describe how everything on the planet came from the same cells he came up with Descent with Modification. Later in his life this was changed to Evolution: the change in the properties of the groups of organisms over the course of generations. By starting with one cell and adapting to the environments around the organism they overtime become better suited for their environment. If you look at a fish compared to a human at first look, we don’t have very many things in common but because we came from the same type of cells, we do have somethings we share. For example, both fish and humans need oxygen to breath but because a fish is underwater, they have gills to get oxygen and we humans have lungs. As our ancestors adapted their descendants became better modified for the places that they live which is why there are many different animals on the planet. Also, as those ancestors were able to survive better with these traits, they lived longer which allowed them to pass on these traits to the next generation which is how they became modified over time. This also describes why when you look at taxonomy for every animal, we start with the kingdom Animalia and then get more specific. Another way to describe Evolution which is what Darwin named “descent with modification” to later is just change over time because an organism can’t evolve but a population can. It is just a way to explain why we have so many different animals to day, that look and sound and act different that the next one but somehow have things in common.
Hello Isabel,
I thought your concept tied into mine rather neatly. While I was looking at gene flow, your descent with modification topic provided another aspect of the dispersion of populations of wildlife. I used wolves as my example wildlife to discuss gene flow, and they have a place here as well. A general ancestor for various wolf populations is going to be the same if we go far enough back in history. But there are various sub-species of wolves that are present today. There are red wolves, arctic wolves, grey wolves; each with different characteristics that have evolved for their specific environments. When evolving to fill their niche, they have remained very closely related genetically, but with different evolutionary trends, leading to their distinct sub-species. The grey wolf is Canis lupus, the red wolf is Canis lupus rufus or Canis rufus, and the Arctic wolf is Canis lupus arctos. All are of the same species, but they have differentiated as they have evolved in their environment. The sub-species developed to better survive in their environments, which is why we don’t have the Arctic wolf in Yellowstone, or the red wolf in the Arctic. They are all very similar in their genetic makeup and evolutionary history, but have evolved to their particular niche.
Further reflection on my original topic, linked to defining evolution and adaptation
I briefly touched on the topic of the adaptation concept in my response to Isabel, regarding the different subspecies of wolves. Adaptation and evolution are linked processes. Over several generations, the evolutionary process leads to adaptations of an animal to their environment. An example of this would be the wolf packs of the Hayden Valley in Yellowstone. While most wolves tend to hunt elk for their prey, the Hayden Valley packs have adapted over time since reintroduction to hunt bison. These are much larger animals than elk, requiring the adaptation to the population. While this adaptation isn’t explicitly an evolutionary one at this point, and more of a result of food availability and pack behavior being passed down through generations, it is feasible that wolves originating from these packs will eventually evolve to be larger and produce a greater number of pups per litter than other wolf packs. This effect will be diluted, however, given the gene flow between wolf pack populations in the Greater Yellowstone Ecosystem.
An additional point I would like to make regarding gene flow is in regards to the vast impact this phenomenon could have, especially if there is a wolf reintroduction program implemented in Colorado, as has been recently approved by ballot initiative. The current wolf population in the Western States is rather limited. As wolves dispersed from the original Yellowstone reintroduction packs, they moved throughout the Greater Yellowstone Ecosystem and beyond. But even beyond this spread, we have records of wolves that have travelled far beyond the bounds of what we would consider their normal restorative range. One wolf has been tracked coming down into Utah and into Colorado. With this level of travel, there could very well be wolf populations all along the Rocky Mountains interconnected by means of gene flow as individuals travel throughout the ranges, meeting with others, and producing new packs. I find the idea of this completely fascinating, and look forward to the research that comes with the potential of a relatively isolated reintroductory population of wolves being established in Colorado.
Finally, the discussion of reflection on the learning I partook during this class:
I found the most interesting concepts to be in the very last chapters of our learning. I was already familiar with some of the topics, with my background studying wildlife. As is apparent with the above comments, I find wildlife fascinating and learn as much as I can about ecosystems. I may not have had some of the level of involvement relating to these topics in my previous coursework, but knowing more of the deep level aspects of evolution and genetic movement provides me with a broader understanding of topics I may have understood on a surface level, but of which I didn’t have true knowledge.