Alison+P.


 * Wikipost #1 - Genetics - February 28, 2014**

__**Huntington's Disease**__


 * What is Huntington's disease?**

Gene mutations happen all the time, some are more common than others, however they occur every day. Some gene mutations can go unnoticed, others can cause physical and/or mental disabilities, and others can be even more serious leading to fatalities. For this wikipost I would like to look into Huntington’s disease. Huntington’s disease is an inherited gene mutation that causes the nerve cells in the brain to break down. This disease causes a problem in movement, processing, and can lead to psychiatric disorders. Sign’s aren’t usually noticed until the ages of 40-50 years. When disease onset develops earlier than the age of 20, usually it results in different forms of symptoms and there is a faster disease progressions. Signs will always occur during the affected human's life time, but when during their lifetime varies. When symptoms start to show, the affected person will die around ten years later.




 * How do you get it?**

Huntington's disease is an inherited disease. If you have it, there is a 50% chance that you will pass it down and your child will be affected with it as well. You have the disease when you have in between 36-120 repeating CAG codons.

This picture demonstrates clearly that only one abnormal copy of the gene is needed to develop Huntington's disease. Frank and Rose had three kids, two of them received one normal copy from their mom or dad, and one mutant copy from their mom or dad. The other kid however inherited the abnormal copy from his father and one from his mother, making him homozygous recessive for the disease.

This picture represents the number of repeating CAG codons on the chromosome. A normal number of repeating CAG codons on the chromosome would be 29 or less. Someone who has the gene, but doesn't express it, but can pass it on, is known as a carrier. A carrier has in between 29 to 36 repeating CAG codons. You can think of a carrier as being heterozygous one abnormal copy of the gene and one normal gene, but since the normal gene is dominant the abnormal allele is not expressed. Someone who has the disease can have up to 120 repeating CAG codons.


 * How do I know if I have it? Is there a cure?**



To find out if you have Huntington's disease, you should do two things. First, you should look in your families history to see if there is any possible chance of inheritance. Even if there is no one in your family chain with Huntington's disease, it is still possible (however very rare) that you have had a spontaneous mutation in one of your genes and you're affected. With that being said, you should also get a blood test done to confirm your possible diagnosis.

At the moment there is still no cure for Huntington's disease; however there are still treatments for people. There are prescriptions drugs (ex. tetrabenazine) that will help control movement. There are also things called dopamine blockers that help reduce odd behavior and extra movements as well.

This video is a fun summary of this wikipost:

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If you would like to read on more information, feel free to click on these links to learn more:

http://www.sciencedirect.com/science/article/pii/S1545534306700414 http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0001775/ http://www.ncbi.nlm.nih.gov/books/NBK1305/

If you have Huntington's disease or know someone who does and would like more detail on treatments and such, please feel free to read the articles provided from this site : http://www.huntingtonsociety.ca/


 * Sources Cited:**

http://www.stanforddaily.com/2014/02/24/student-screens-documentary-examining-huntingtons-disease/ http://www.netdoctor.co.uk/ate/neurology/205066.html http://www.mayoclinic.org/diseases-conditions/huntingtons-disease/basics/definition/con-20030685 http://ghr.nlm.nih.gov/condition/huntington-disease


 * Wikipost #2 - Evolution - May 2, 2014**

__**Lamarckism vs. Darwinism**__


 * What Lamarck believed:**

Lamarck is known for his //Theory of Inheritance of Acquired Characteristics// that he brought forward in 1801. His theory stated that if an organism changes to acquire an advantage in their environment, that changed characteristic is passed down to the offspring. For example, Lamarck believed that giraffes used to have stumpy necks, but when their food became out of reach, they NEEDED their necks to elongate to reach for food; to survive. When the giraffes developed these long necks, their offspring would inherit the trait as well. Lamarck also believed in the theory of 'Use and Disuse'. If organisms don't require certain traits and/or body parts, they begin to fade away. After time, the trait and/or body part will disappear entirely from the organism. He also believed that evolution is already predetermined. Meaning that all outcomes are already decided.




 * What Darwin believed:**

Darwin's thoughts were contrary to Lamarck's. He believed in natural selection. Darwin thought that changes in an organism's life don't affect the evolution of the species. He also stated that the desires of the organism have no relation with how they evolve. He said that organisms are all different, and that even those of the same species come in different variations. Organisms who have gained characteristics that give them advantages are the ones who survive and who create more offspring. Basically survival of the fittest. Those who fit their environment well were the ones who survived; the ones who survived were the ones who reproduced more successfully. The organisms who didn't adapt well eventually died off.




 * Why we believe Darwin:**

Darwin's theory had plenty of evidence to support it. First off, the Theory of Inheritance of Acquired Characteristics was disproved after some experiments that showed that offspring did not inherit the the changes of the organism during their life. The second way Lamarck was disproved was from our current knowledge of genes. We know that genes what's inherited and passed on, and genes cannot be affected by the outside world.



A 3 minute recap:

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If you would like to learn a little more in depth on the topic, feel free to click on these links:

http://necsi.edu/projects/evolution/lamarck/lamarck/lamarck_lamarck.html http://www.darwins-theory-of-evolution.com/ http://evolution.berkeley.edu/evolibrary/article/evo_25




 * Sources Cited:**

http://evolution.berkeley.edu/evolibrary/article/history_09 http://evolution.berkeley.edu/evolibrary/news/140403_rootworm http://www.biology-online.org/dictionary/Natural_selection http://sciencenetlinks.com/student-teacher-sheets/lamarck-and-darwin-summary-theories/