Natasha+Gallant

= __ Wiki Post #1 - Genetics; January 14th 2013 __ = =**__Progeria__**=

Progeria is an extremely rare genetic disease also known as "Hutchinson-Gilford Syndrome". It is a disease in young children where the aging process of the body speeds up much faster than what it would in normal humans. The aging process rate in the children affected with this condition increases to about seven times the normal rate. Because of the increased aging in these children, a child that is 10 years old would appear and look as though the child was about 70 years old and might also have conditions that you would often see in elderly people, for example arthritis. This disorder is so rare that in fact it only affects about 1 in every 8 million births on earth, and those living with this genetic disorder would be expected to live to only their mid teens or early twenties and the cause of death is usually from a stroke or heart failure. The photo above is of a little girl names Haley Okines who had this condition but sadly passed away not too long ago. You can read more about her here where her parents made and dedicated a page to her : []

A child with progeria usually develop their first symptoms in the first few months of their life on earth, and later experience other symptoms such as skin changes, abnormal growth,teeth decay and hair loss. A child that is expected to have progeria would be sent to complete many different tests including; cardiac stress testing to show signs of early atherosclerosis of the blood vessels (which is a disease in the arteries defined by the deposition of plaques of fatty material on their inner walls), physical exams or laboratory tests to show symptoms of insulin resistance or skin changes, as well as genetic tests that will detect changes in the gene of the child that causes the rare genetic disease. There is no treatment for progeria however the child may be given medication and others tests to help deal with other diseases that come along with this condition such as arthritis, or heart disease.

//The photo on the left shows some of the symptoms of a child with progeria and some of the problems that they have to deal with throughout their short life time. As well as the photo on the right showing the different stages.// media type="youtube" key="8D4S3pDjPiU" height="315" width="420" align="center"

//This video is a girl named Ashley Hegi who also suffers from progeria and she talks about her life and what she enjoys doing and about the disease that she suffers from.//

The exact cause of this disease is not known but they believe that it is caused by a single abnormal gene called the lamin A gene that makes protein essential to hold the nucleus of the cell together. And both parents of the child would both be normal and no one can be a carrier of progeria, it is a dominant mutation so there would be one normal copy of the gene and one abnormal copy of the gene.

The following chart down below is to show how a cell affected with the rare condition of progeria differs from any normal cell: //The above picture shows another child with the disease along with on the top right is a normal cell and the bottom right shows a cell of a person with progeria, as you can see the different shape of the cells as mentioned before.//
 * Steps in a normal cell || Steps in a cell affected with progeria ||
 * The gene LMNA encodes a protein called prelamin A. || The gene LMNA encodes a protein called prelamin A. ||
 * Prelamin A has a farnesyl group attached to its end. || Prelamin A has a farnesyl group attached to its end ||
 * Farnesyl group is removed from prelamin A. || Farnesyl group remains attached to prelamin A. ||
 * Normal form is called prelamin A. || Abnormal form of prelamin A is called progerin. ||
 * Prelamin A is not anchored to the nuclear rim. || Progerin is anchored to the nuclear rim. ||
 * Normal state of the nucleus. || Abnormally shaped nucleus. ||

If you want to find out more about this you can read these links they all talk more about progeria and go more in debth and are really interesting readings. The last link is a cbc report article on a girl who is doing a drug experiment to see if it helps with her progeria. [] [] []
 * Further Readings:**

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 * __Sources Cited__**

= __ Wiki Post #2 - Evolution; January 17th 2013 __ = **__Evolution Of A Dolphin__** About 95 millions years ago the ancestor of today's dolphins appeared on earth, this ancestor is known as Mesonix. It was a terrestrial animal meaning that it went into the lakes and waters to get food.This ancestor had hind and front limps that had bones to help support the weight of the Mesonix. Over the years it began to become more adapted to being in the water and eventually starting to not come on land at all.

//The above photo shows what scientists believe the dolphins ancestor, Mesonix looked like.//

Over time the hind and front limps evolved into pectoral flippers which is what is known as the cone structure that you can find in the pectoral fins of dolphins today, and the original limbs found eventually began to disappear over time and the rod-shaped pelvic bones found in the vestigial hind limbs of today's dolphins over time replaced them.

​//This photo on the left shows the difference between a human arm and arm of the dolphin. This photo on the right shows how the skeleton of the Mesonix evolved into the skeleton// //of the dolphin today.//

Millions of years later the Mesonix evolved into the dolphin we know as today. As evolution took its role the nostrils of the Mesonix slowly started to get further and further away from the nose and began to show up on the top of the head. This evolutionary change made it much easier for the creature to breathe while it was swimming around in the water. As well the size and shape of the skull became larger and then the development of the fat pad in the lower jaw began to arise. This extends to the middle fin and it helps dolphins be able to hear as well as they do. Today's dolphins remain in the water their entire life and since they are weightless in the water their bones do not have to carry around as much weight as the Mesonix did. This caused the bones to evolve into a much lighter bone than in the Mesonix.

//The above picture shows the gradual change in the appearance of the Mesonix into today's dolphin.// media type="youtube" key="m2NZV7p8_Zs" height="315" width="420" align="center"

//This video goes much more in depth about how the dolphin evolved involving the skeleton, fins, etc.//

[|Dolphin Evolution Article]- This is a short article explaining more about how dolphins evolved over the years. [|Interesting Questions]-This explains more about how dolphins evolved as well as shows various questions related to the evolution of dolphins. [|Dolphin Evolution]-This is an article going more in depth about the evolution of dolphins [|Dolphin Evolution Facts]- This link has a lot more information of the evolution of dolphins and tells you interesting information.
 * Further Readings:**

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 * Sources Cited**

= __Wiki Post #3- Body Systems; January 17th 2013__ = =__ Central Nervous System __=

The central nervous system is made up of two parts, the brain and the spinal cord. The brain and the spinal cord are both bathed in a cerebrospinal fluid that protects the brain and spinal cord, as well as supplies nutrients and takes away the waste. This cerebrospinal fluid is protected by a sack of three layers of tissue that holds as well as protects the brain and spinal cord. The spinal cord runs down your spine and the bones protect it from getting damanged, a thick bundle of nerves make up the cord that connects the rest of your body to your brain.

//The photo on the left shows what the central nervous system is made up of, which is the brain and spinal cord. The photo on the right is showing the meninges or the three layers that protect the spinal cord and brain as well as the cerebrospinal fluid.//

=__ The brain __=

The brain keeps the whole body in order and makes everything do what it's suppose to do. It controls all of the body systems and organs and makes them work they way that they should. The brain lets us all be able to think, feel and remember things, it basically makes us act like human beings. The nerves and spinal cord allows the brain to communicate through them with the rest of the body. Your brain has many different parts that all work together, but there are a few key parts that are the most important parts of your brain. //This is an image of the brain and some of its different parts and where they are located on the brain.//
 * The Cerebrum**

The cerebrum is the biggest section of the many folded regions. A longitudinal central fissure goes through the middle of it dividing the brain into two parts also known as hemispheres. The right and left hemispheres that are connected by a corpus callosum, and the right side of the brain controls the left side of your body, and the left side of your brain controls the right side of your body. The cerebrum controls the voluntary actions and is divided even further into four lobes.

//The picture above shows each of the lobes in the cerebrum.//


 * The Cerebellum**

The cerebellum is located at the back of the brain and is a lot smaller than the cerebrum is and is also known as the "little brain". This is the part of the brain that controls balance, coordination, and movement. The cerebellum is also involved in language although scientists poorly understand this point.


 * The Brain Stem**

The brain stem is located behind the cerebrum and in front of the cerebellum. The brain stem connects the rest of the brain to the spinal cord that runs down your neck. It is in charge of all of the functions that your body needs in order to survive and stay alive, such as circulating blood, breathing, and digesting food. The brain stem mediates the flow between the body and the brain.


 * The Pituitary Gland**

The pituitary gland is extremely small and its job is to produce hormones and release them into your body. This part of the brain plays a big role in puberty, and is also responsible for amounts of sugars and water in your body as well as your metabolism.


 * The Hypothalamus**

The hypothalamus is the connection between your endocrine system and your nervous system. This part of the brain is what controls your body temperature. If you are too hot it will tell your body to sweat, and if you are too cold it will send signals to your body for it to shiver. media type="youtube" key="yq6GJ1yj3HA" height="315" width="420" align="center"

//This is a video of a person describing the central nervous system with a visual of the brain.// **Further Readings:** [|Your Brain and the Nervous System]- This goes in depth more about the nervous system and brain and tells you the different parts of the brain, etc. [|Brain Parts And Functions]-This link tells you more about the parts of the brain and each of their functions. [|Nervous System with Sheep]-This is a neat animation that shows the signals through the nervous system in a sheep. [|3D Brain]-This is a neat animation that lets you explore the different parts of the brain.

**Sources Cited** __[]__ __[]__ __[|library.thinkquest.org/5777/ner1.htm]__ []

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