Friday, December 5, 2008
Tuesday, December 2, 2008
The first staining procedure we did for Microbiology lab this semester dealt with the Gram Stain. The stain was, “…named after the Danish bacteriologist who originally devised it in 1882,”is done in order to allow for the classification of bacteria as either gram positive or gram negative, often for diagnostic purposes. The procedure consists of the following basic steps: a drop of primary stain (crystal violet) is applied to a heat fixed smear of the bacteria of interest, leaving all cells stained purple initially. Secondly, the bacteria are washed using distilled water and a single drop of IKI or Gram’s iodine is then applied over the smear so that CV-I complex crystals may be allowed to form. Next, after another washing with distilled water, ethyl alcohol or the decolorizing agent is applied so that the thin outer layer of gram negative bacterial cells is dissolved away, allowing for the loss of the primary stain in this particular type of organism (while the thickly walled gram positive bacteria are capable of retention of the CV-I complex). Lastly, after washing the decolorizing agent off with distilled water, the counterstain, Safranin, is applied so that the gram negative bacteria may be identified or colored by this reddish-pink dye. Therefore, when viewed microscopically, the gram negative cells are expected to appear pink in color (retain the counterstain color, Safranin) since the CV-I complex typically would have been washed out when treated with ethyl alcohol. However, because the cell structure of gram positive cells consists of a much thicker peptidoglycan layer (which allows for greater retention of the CV-I complex), those bacteria which are gram positive are expected to appear purple in color when viewed microscopically.
Monday, December 1, 2008
The second argument was based on the evolutionary importance of preserving biodiversity. By not driving a variety of species to extinction, we allow for the possibility of further evolution. The more species that are allowed to thrive (for a longer period of time), the greater the chance some of those species will be able to give rise to new species. Furthermore, these new species may play crucial roles in the future evolution of the world’s genetics.
The final argument for biodiversity was philosophically based. Essentially, the importance of preserving our Earth’s biodiversity is determined by how humans choose to respond to this crisis we have created. Humans are capable of acting to preserve the biodiversity of the planet and until this understanding is realized, the devastating rates of extinction which we are causing will continue to devastate the planet. I feel the most compelling argument would be the final one since it takes into account the importance of human ethics and morality. It discusses how humans may be heavily swayed by the economic and evolutionary repercussions of our destructive behavior, but what ultimately dictates how we will deal with the situation is our own consciousness.
Within a population, there are bacteria with varying levels of antibiotic resistance; therefore it is easy to determine that the condition of variation is being met. The administration of antibiotic medication results in those bacteria with the genetic capacity to resist termination to survive, while those bacteria lacking the necessary genes for tolerance to the treatment are eliminated. Additionally, there are differences in how a bacterium may acquire its resistance to antibiotics in order to achieve increased chances of survival: transformation, plasmid transmission and spontaneous mutation. Collectively these varied conditions set the stage for natural selection to occur.
Furthermore, once the antibiotic takes effect and bacteria lacking resistance are destroyed, those bacteria which do survive readily multiply and in doing so confer resistance to the next generation. As the cycle repeats, one can see natural selection at work. With so many different possibilities, so many different ways for bacteria to survive and multiply it is evident that the conditions are ripe for bacterial antibiotic resistance to continue evolving through the process of natural selection.
Thursday, November 27, 2008
Wednesday, November 26, 2008
Saturday, November 22, 2008
Thursday, November 20, 2008
I had to read an article out of my Ecology lecture text and then write about it so I figured I'd just blog about it as well. Mutualism exists between flowering plants and their pollinators-bees. Plants benefit from this relationship in that they greatly increase their chances of reproduction. The chances of having their pollen grains fertilize another flower are much more probable if they rely on a pollinator like the bee who moves among many flowers in a short amount of time, rather than simply relying on the unpredictability of the wind for reproductive purposes. Flowering plants invest a substantial amount of energy in pollen production and so by utilizing bees as a vehicle for carrying out pollination they are increasing their energy efficiency. The bees benefit by extracting nectar from the flower and then internally converting it into honey (“a high quality energy store”). Once the bees inadvertently pick up the pollen grains, they may consume the highly nutritious grains which are rich in proteins and oils.
A host-parasite relationship exists between bees and two mite species: Varroa and Tracheal. The cost to the host (bees) is their mortality and fitness. The Varroa mite benefits from the relationship by deriving sustenance from the internal fluid of the bee. The Tracheal mite derives nutrition from its host’s body, but also uses this medium as a site for reproduction. Due to varying levels of exposure to the parasites, different host species have developed differing levels of resistance. Often, the more time a bee species is exposed to a parasite, the more likely it is able to develop resistance to the pest and survive if attacked.
I don’t like getting 3.5 out of 5 points-I really thought I had earned better. I didn’t half a** it, you know??? Stray letter…how could I have missed that? The proof is not in the pudding, HAH, I knew that didn’t make sense! Slap, you got rejected, so be tenacious. These are some of the thoughts that flow through my mind as I sit there in Biological Writing sometimes. Dr. Baines picture perfect dog is named Dargo…I didn’t hear her explanation of that? I know she said something about Dr. Zen understanding the significance of the dog’s name because he’s ‘nerdy’ too and into some old comic or something like she is. As I’m proofreading this I feel like circling behaviour and writing ‘This looks funny because I’m not Australian, British or Canadian but I know it is right.’ It’s just that I wanted to comment on it to see if I could get a chuckle out of Faulkes. Haha, as I’m typing this out, the computer agrees with me. What happens if I type colour? Haha, denied again! I really hope I didn’t get any Ethidium Bromide on my sandwich…I don’t want to die yet, honestly, I’m still young and spry. L.o.l., I know that’s totally not up to me, whatever. I don’t see any grammatical or spelling errors on this second page-damn!!! And I need to get to lab!!! What’s wrong with my brain today?!? Props to Dr. Zen because I could never care about “digging” so much, really. Some people make vicious comments. I seriously need to blog. I’ve been avoiding that and it’s festered and grown like an ugly fungus in a dark corner of my mind. Rejection is not final…Really? Could this be true even if my writing consistently contains serious structural errors? I could work on that though…but how? I know, I know, I’m venting but that’s life, so it counts as a biological topic.
These are my descriptions and interpretations of again, the "Trials of Life," DVD. This blog entry is most concerned with interesting examples of mimicry and mutualism in nature.An example of mimicry would be when the walking stick imitates the appearance of leaves in order to achieve a camouflaged look and guard against its predators. The Praying Mantas mimicking the flowery color and appearance of the white orchid while it lies in wait for its prey is another example of mimicry in nature.
One example of mutualism would be the relationship between shrimp and the Gobi. The two species live together in a cave excavated by the shrimp. In return to the shrimp, for having provided the home the share, the Gobi, with his excellent eyesight serves as a guide and protector of the blind shrimp. The shrimp stays in contact with the Gobi by constantly touching the fish with his own antennae. Through this connection the Gobi can tell the shrimp when it is safe to wander out of the cave or when to stay within because predators are in the vicinity. This relationship is symbiotic because they need each other in order to survive. A second example of mutualism would be the relationship between deer and monkeys. In this instance, the monkeys forage in trees and in doing so, drop leaves which the deer pick up and eat. When the monkeys wander down to scavenge for food on the ground, the deer act to warn the monkeys if a predator comes near so that the primates may escape safely back up into the tree tops. This represents a non-symbiotic mutualism since both species could survive without each other and so they have a facultative relationship with each other. These relationships are both good examples of co-evolution because they demonstrate adaptations and contribute to the continued survival of each species involved.
This is just a continuation of my notes and interpretations of the material covered on the Trials of Life DVD. This blog entry focuses more on predator-prey interactions though. An example of a prey species defending itself against predators would be when certain trees develop poison within their leaves in order to deter herbivorous spider monkeys. The monkeys have adapted to this defense so that they are capable of ingesting small amounts of the poison while feeding. If they have had enough poison they simply move on to another plant and may continue eating. A similar situation occurs when particular types of plants are consumed by beetles. Again, the plants produce poisons to defend against its predators, but do so in a way where the poison is produced specifically in the center of its leaves. The beetles have adapted and overcome this defense by puncturing the leaf, causing the milky poison to drain out, and then feeding safely on the end of the leaf. These are good examples of co-evolution because in each case, the two species involved in the predator-prey relationship developed mechanisms to preserve their own survivorship.
Last Wednesday I was forced to stay in Ecology lab and watch a DVD called, "The Trials of Life," which because of the length, I found somewhat boring. Some parts of it I did find interesting though. So because its all about adaptations and I took notes while watching the DVD, I think I write a few blogs about it. Here I go. One specific [behavioral] adaptation of a particular type of prey (in the rainforest environment) would be the Trinidad Tree Frog developing an aquatic nursery to keep its embryos safe from predatory fish. The adult frogs house their developing embryos in a small sphere of sticky jelly (on tree branches, above water), which will dissolve away once the offspring reach a mature stage of development. This then allows them to fall into the main body of water below and complete maturation. The point of the behavior is that the frog embryos are kept away from the predatory fish until they have outgrown their vulnerable infancy stage and developed well enough so that they may be able to defend themselves against attackers. A specific example of adaptation involving partners in a mutualism would be how the shape of the Saber Wing Hummingbird beak has developed so that it fits perfectly with its food source, the Columbian flower. The hummingbird derives nectar from the flower and the flower benefits from the relationship by having the hummingbird carry out its pollination.
Saturday, October 11, 2008
Saturday, September 20, 2008
I think I can see the effects of all the things I am stressing over physically. For instance, I am seeing laugh lines around my mouth which I thought were not supposed to appear until I was in my late twenties or early thirties according to the women I hear complaining on Oprah all of the time. I think it’s the lack of sleep though mostly. I have read in various places that sleep deprivation accelerates the aging process and just recently I learned that it also may factor into increasing the severity of a number of common ailments in old age. I heard O.B./Gyn. on Oprah say once that lack of sleep changes the way your body metabolizes foods and that was when it clicked for me. I understood the links between food, sleep and functioning at least somewhat. It's all interrelated and sleep is like the physiological cornerstone. I need to sleep better and that's the point I'm driving at. A friend of mine put it in perspective when she admitted that she had fallen asleep in the library before class. I think that's just a sign you're pushing yourself a little too hard and you need some sleep, some time to rejuvenate yourself. But she realized it herself and said she was going to go home and take some downtime for herself. It's just finding a balance between work, play and sleep-duh right? No, actually I think we all understand that on some level, knowing that life needs balance is common sense but achieving that balance is what I think gets most of us. So maybe I should go work on striking my balance and get some rest huh? Haha. I'm a piece of work-stressing about stress!
Saturday, September 13, 2008
Also, I was thinking about trying some lobster before this past Wednesday but after the whole "nociception" discussion (even though I think Dr.Z just used the session to reveal what a farse that woman's argument was) I felt guilty about wanting to try it (I've never tasted lobster before). Now I wonder if Dr. Z has ever had lobster and whether or not he thinks it's humane to consume the animal. It's stupid, but I never thought about the fact that even though I think certain animals are tasty, they have brains and can feel pain. I didn't mean for that last part to rhyme, it just came out that way. But I eat the meat of cows and chickens nearly everyday and I'm pretty sure the same is true for them, so maybe I should just stop being so hippocritical and eat some pasta or something else instead. This is getting too ethically touchy so I'll stop here. Plus I don't think I could handle being a vegan and it's getting late and I got a ton of other work to get to so I have got to end this now. Goodnight bloggers, see you in class Monday hopefully.
Oh and about the yeast: I got a call from my friend who’s just spent her first week teaching high school freshman biology. She wanted to make the class interesting and use experiments to help reinforce the concepts she’s teaching them. So she was trying to mix yeast, water and sugar together in the right proportions so that when these ingredients are heated then placed into a balloon, they expand and inflate it. She wasn’t given specific amounts of how much of each ingredient she should use so she did some troubleshooting and finally after multiple attempts and much frustration, enjoyed success! She called me when she finally got the experiment to work and I was happy for her. I liked my high school freshman biology teacher (she was a sweet lady) but to be honest, I didn’t learn a single thing about biology that year because all we did was hurriedly copy biological notes from the overhead and turn them in for a grade. Sorry, but I don’t learn like that. At the end of the year I still didn’t even know how to properly draw out a Punnet square! I just wanted to mention it because I think my friend’s enthusiasm over the inflation of the balloon is noteworthy. I would have preferred to have someone like her as my teacher any day out of my freshman year in high school. Just a thought, you know.