Saturday, February 26, 2011

Are We There Yet? (The Joy of Maps)

Before I go into too much depth, I'll give credit where credit is due.

We've recently been studying the madness of chromosome mapping over the past few days, so I thought I'd give a quick overview. So...here we go!

Chromosomes can be viewed as similar to a thumb. A thumb has two separate regions, split by a knuckle, one of which is clearly longer than the middle. Similarly, a chromosome has two arms, a p arm (shorter) and a q arm (longer). These arms are split by a notch known as the centromere.

Bizarre analogies aside, let's take some time to look at a specific gene on the X chromosome: Xq28.

Let's look at what each subset of this cytogenetic locus means:

X

This simply means that this particular gene (MRX28) is located on the X chromosome (more on the significance of this later!).

q

This means that the gene is on the longer of the two arms of the chromosome--the q arm.

28

This means that this gene is on the band labeled 28. Chromosomes, when stained, show different bands. This is caused by the differing ways in which the DNA is wrapped.

Now, I chose a gene on the X chromosome for a reason. Genes on this particular chromosome are known as "x-linked." Abnormalities on the X chromosome are always apparent in males because there is not a dominant allele on the X chromosome to mask the presence of the mutant allele. For an example of this, consider color blindness. Men are color blind for red and green more often than women because the gene(s?) for detecting red and green light is on the X chromosome, and men only have one copy of the X chromosome, so defections are not masked.

The MRX28 gene I mentioned earlier is one that has been linked to mental retardation. Here are some examples of other x-linked genes and the symptoms mutations carry:

COL4A5 (Xq22)

This is the gene that causes Alport's syndrome. This syndrome damages the various blood passages within the kidneys, which leads to urine in the blood and less effective filtering by the kidneys.

ATP7A (Xq21.1)

This particular gene causes Menkes syndrome, in which the body cannot absorb enough copper. This can affect the structure of many organs within the body (including skin, hair, and nerves) and often leads to a low body temperature and bleeding in the brain.

MECP2 (Xq28)

This gene is the root of Rett syndrome. This is usually found in girls because, although a defective X chromosome can make it to a boy, the boy will not survive. A girl, however, because she has two X chromosomes, is typically strong enough to live with the syndrome. Symptoms of Retts include problems breathing, seizures, and loss of sleep.

On a slightly cheerier note, I would like to relate an accomplishment of mine that is directly related to this. While I was having my hair cut, I made a joke about already going bald. The lady cutting my hair then asked if my mother's father was bald. Although my mother was adopted, I began to realize something: the gene that causes baldness is probably on the X chromosome. (I haven't actually researched this, but it seems likely.) This would also explain why women tend not to go bald--women have two X chromosomes, so they would not suffer the symptoms of a defective X chromosome as often.

Is that right? 

Eugenics

Well, I've thrown together an extremely (for me) short prezi on the origins and impacts of eugenics.

I also really recommend the Eugenics Archive, which was also extremely influential in the development of this post.

Have fun!

Here Come the Biology Posts!

Just a heads up for everyone who reads this blog for the education perspective: Over the course of today, I will be releasing a slew of posts whose purpose is simply to show my (hopefully!) developing knowledge on the subject of genetics.

Mr. Ludwig and I had a little discussion about whether or not I should spin Education off into an entirely new blog or not. We bounced back and forth on the sides for a while, with him starting off by promoting a new blog, converting me, but then he switched back to keeping them all on the same blog. His justification was that by maintaining one blog, I could keep my studenthood in the forefront of my readers' minds--which, after all, is what this is all about, right?

This raises an interesting question: What am I doing here? Can I really provide an unbiased picture of what education is like for the student, or will I simply become a parrot, repeating what everyone else has already said? After all, my instinct is always to empathize with a teacher, and I can't really see myself actively criticizing someone whom I have no knowledge of.

I'll be back with more later today, but for now...biology! 


Wednesday, February 16, 2011

Change

The URL is now changing to

http://mreeseducation.blogspot.com

Hope to see you soon!

Tuesday, February 15, 2011

The Quintessential Question

Recently, I was examining a grade sheet for a class whose grades are calculated by adding up all of the points earned and dividing by the points possible. I admit that's not too exciting. However, my mind needed some form of distraction and started playing around with the numbers on the sheet. Then, I began to notice some anomalies.

Consider the following situation, which I put into a graph:



There are two students, Bob (the black line) and Joe (the red line) whose understanding of the content material does not match their grades.

Allow me to explain this (unrealistic and overly simplistic) situation. There are two students, Joe and Bob. Their understanding of a certain idea will be mapped by five various assignments (worksheets, tests, etc.) and will be averaged together at the end for their final grade on this concept. Each assignment is worth one hundred points, and no one assignment will be weighted above the others in the final averaging.

Now, Bob's (black line) understanding of the subject is superior to Joe's (red line). However, on the day of the first assignment, his girlfriend breaks up with him, his grandmother dies, and he falls on ice and breaks his arm. He's somewhat distracted, and he lets it get to him--in fact, he only earns 60 of the 100 possible points. Joe, however, is having a good day and is able to guess his way through this assignment (it's all multiple choice) and aces the paper. In addition, he brought in a box of Kleenex, so he was able to tack on 10 more points to his "grade."

Here's where the problem comes in. Bob actually understands the subject matter, and is able to receive all of the 100 points possible on the four following assessments of his knowledge. He is consistently able to demonstrate that he knows what he is talking about.

Joe's luck, however, does not continue to hold out. On the next assignment, he only earns 95 of the potential points, then 90, then 85, and so on, losing 5 points from his score each time. If these assessments are truly gauging the knowledge these students have, then shouldn't we conclude that Joe does not fully understand the material--and shouldn't we also conclude that Bob's grade should be higher than Joe's?

However, at the end of the series of assessment of knowledge, Bob's and Joe's grades are equal--a 92%, 460 points earned out of 500 points possible. Although I may be becoming a parrot, this is the primary flaw with using averages to determine a grade: averages include the history of a student's understanding instead of the student's current understanding.

This seems to be the question every edublogger asks: Which is more important, the history or the present?

To me, it's clear that the answer is the present. What about you? 

One Day!

Just a reminder that, tomorrow, at 12:00 P.M. Eastern Time, this blog's URL will change to www.mreeseducation.blogspot.com. Hope to see you then!

Monday, February 14, 2011

The Grading Instinct



I have a nine-year-old, incessantly creative sister. Yesterday, we were taking a Sunday afternoon walk when she had an idea: Why can't we clean the water in gutters before depositing it in oceans? (I have a feeling that the water cycle has been stressed in her science class lately.) 

After we made it home, she continued developing this idea--to the point of writing a "book" on it (complete with table of contents). Once it was finished, she proudly walked up to Dad, handed it to him, and said, "What grade would you give this?"

Grades. They're the nemesis of students (and many teachers!) everywhere. But I must say that I think it's somewhat sad when the first thing a nine-year-old can think of after she's finished an independent project is to ask for a grade.

At the risk of recycling what every other edublogger has ever written, it seems to me that the real question is what role grades play in an educational system. Are they superfluous and redundant and have no real meaning, or are they a vital and essential system that tell all of the knowledge a student has?

I intentionally overstated both sides of this story so that the strengths and weaknesses of both sides could become more apparent. But still, does a report card with simply a final letter grade really give anything but an overview of a student's "knowledge" within several different subjects? What about the overlap within certain subjects? After all, most physics classes depend at least somewhat on mathematics. Should there be a way to display the student's understanding of the overlap of these materials?

Then, we should spend some time evaluating the role that grades play within the lives of students. The prime example here is my sister asking for her "grade" on her book. She felt that she would not know the value of the work if she did not have a grade on it. She also attends a school where, like many schools, late work earns a zero. Of course, this drives me crazy. After all, all it really says is that if you don't demonstrate understanding of a certain topic by a certain date, you must not understand the topic.

Right?

I've intentionally left many questions unanswered here, simply because I don't feel that I have the level of expertise necessary to answer these questions. However, I do want to know what you think. Let's share ideas and see how this develops.

Sunday, February 13, 2011

A New Chapter

Most of you know that this blog began as a class requirement--the place where I put my various posts involving various topics such as the properties of water or photosynthesis.

I've been looking around the edublogosphere more and more lately, commenting on various blogs and trying to share my ideas. However, this means more and more people have been coming to my blog--and I'll be honest: I don't currently feel that this blog has enough substance to warrant this attention.

So, I know announce a new chapter in the life of this blog. It will continue to play host to my musings on biology, but those posts will probably be far less frequent than those concerning my outlook on education in today's society. I hope to be able to provide something to the debate most of the edubloggers cannot--the student's perspective on what happens within schools.

In addition, the URL of this blog will change to

http://www.mreeseducation.blogspot.com

on Wednesday, so if you would like to continue receiving my posts (and I think they're about to become much more interesting!), I'm afraid you will have to resubscribe after this change is made. I simply wanted to give everyone ample warning before officially changing it.

To be honest, I'm a little nervous about this change. So many edubloggers are so knowledgeable and experienced that I can't help but feel like an uninitiated upstart that will only end up seeming somewhat naive. I hope that you will be willing to bear with me and hope that we can all learn from this experience. 

So begins the new chapter of Education from the Student's Perspective.
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