Jake+D.

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=Wiki Post #1-Genetics: March 21, 2013=

There are many different forms of gene mutations that occur in the DNA, DNA replication, and some unpredictable. They come in different forms and severerities. Some mutations do not affect humans, some can go unoticed, some can even be helpful for newly developed proteins and functions of the body and then there are the serious and even deadly mutations. The serious mutations also come in many different forms and one of these diseases is called __Huntington's disease__. This disease is inherited through families where the nerve cells in certain parts of the brain waste away and degenerate. When the gene is passed down through the family the child has a 50% chance of having Huntington's disease sometime in his life. If the child doesn't get this gene then he cannot pass it down to his children in the future. This picture shows how children have a 50% chance of inheriting the Huntington's Disease when you have one affected and one unaffected parent. Huntington's disease is inherited in an autosomal dominant fashion. The probability of each offspring inheriting an affected gene is 50%. Inheritance is independent of gender, and the phenotype does not skip generations.

What is Huntington's Disease? A video to help you understand what Huntington's Disease is actually all about.

media type="youtube" key="4HgFUvVyHYQ" height="315" width="560" Huntington disease is a progressive brain disorder that causes uncontrolled movements, emotional problems, and loss of thinking ability (cognition). - Adult onset of Huntington's Disease is the most common and symptoms start to occur from ages 30-50 and the people diagnosed with the adult onset will live 15-20 years after symptoms start to occur. -Childhood or adolescence onset of Huntington's Disease is less common but nonetheless still occurs. Their life expectancy is 10-15 years after symptoms start to appear.



Huntington's disease onset ages. The age at onset distribution in Huntington's disease is very broad and may vary ffrom as young as 3 or 4 years of age to as old as 85.

Symptoms:
Early signs and symptoms can include irritability, depression, small involuntary movements, poor coordination, and trouble learning new information or making decisions. Huntington's Disease is also sometimes called Huntington's Chorea because of the involuntary jerking and twitching movements the people have which is known as chorea. Affected individuals may have trouble walking, speaking, and swallowing. People with this disorder also experience changes in personality and a decline in thinking and reasoning abilities. In children who are affected by this disease early symptoms will include clumsiness, slurred speetch and drooling. As well as some symptoms from the adult onset. School performance often declines as thinking and reasoning abilities become impaired. Seizures occur in 30 percent to 50 percent of children with this condition. A microscope image of Medium spiny neurons (yellow) with nuclear inclusions (orange), which occur as part of the disease process, image width 360 µm

How Huntington's Disease occurs? What genes are involved? This disease is caused by a genetic defect on chromosome 4, a mutation in the HTT gene. This gene is instructions to make the protein called huntingtin which is a protein that appears to play a very important role in the nerve cells in the brain. Huntington's disease is a chromosomal mutation that involves the duplication of CAG too many times on the HTT gene. An increase in the size of the CAG segment leads to the production of an abnormally long version of the huntingtin protein. The longer protein is then cut into smaller, toxic fragments that bind together and accumulate in neurons, disrupting the normal functions of these cells. When the neurons are disrupted and eventually die is when symptoms start to appear. Normally the CAG segment of the HTT gene is repeated 10-35 times but people with 29-36 repeats can carry it but won't become affected, people that have it repeated 36-40 times may or may not become affected and then the people with this segment repeated 41-120+ times will almost positively develop the disorder.

More information about the HTT gene can be found here: []

More info on the Huntington's Disease: [] More information on inheritable diseases: [] Some statistics on Huntington's Disease: []

Sources: [] [] [] []

=Wiki Post #2- Genetics again: April 10,2013=

__Albinism:__
Why is it some animals are albino, white skin colored? How rare is it? Can it be passed down through genes? These are all questions I have wondered, especially since I am a hunter. I have always wanted to see an albino deeror moose, but are there other albino animals? In fact yes, in North America there has been over 300 different species reorted of having an albino sighting or documentation. This incudes animals from cockroaches to apes and yes, even humans. Any animal that makes less than a normal amount of a protein called melanin, which is a pigment, can have albinism.

A baby wallaby and a squirrel who hav albinism. You can see that it produces less than normal melanin because the skin and hair is white and the red eyes.


 * How melanin works?**

We make melanin in some specialized cells. The melanin colors our skin, eyes and hair. Since it can absorb every wavelength of light, melanin protects our skin from damage by the sun's ultraviolet rays. It also helps our eyes develop and handle visible light properly. This meansthat they can develop cancer easier because they are more sucsceptible to skin cancer and as a result have to stay in the shade on sunny days. Albinism is caused by mutations in the DNA passed from parent to child, and is pesen at birth. Albinism is like a manufacturing problem and starts with the melanocytes. Melanocytes are located in the bottom epidermis of the skin, the uvea part of the eye, inner ear, hair follicles, etc. Albinism occurs when melanocytes cannot make enough melanin to color hair, skin and eyes. Melanin also provides essential protection from ultraviolet rays.

Melanocytes manufacture melanin. Manufacturing begins when melanocytes, following instructions in DNA, construct melanin-making enzymes and the amino acid tyrosine. This production takes place in sacks calld melanosomes. These sacks take in the enzymes and tyrosine.Inside melanosomes, the enzymes, acting as catalysts within the cells, begin a long series of chemical reactions in order to convert tyrosine into the two types of melanin humans have. These are eumelanin, which is brown or black, and pheomelanin, which is red or yellow. Once melanosomes are packed with melanin, melanocytes ship them away to keratinocytes, barrier cells in the topmost layer of the skin and the iris in the eye and into our hair. How many that are shipped, and the mix of pigment is what gives us our color of skin, hair and eyes. It is not bad at this point if you have a lck of melanin or not it is when the sun is beating down on you. As UV rays can damage DNA the melanin acts like a bleachand covers the nucleus of th skin cells; however, when there is a lack of melanin it cannot do this and the skin ismuch more sensitiveto UV rays. The process of melanosomes being released, distributing into the cells and then being released to cover the nucleus and protct it from the sun.

How rare is it?
Researchers observe that albinism occurs once in every 10 000 mammal births. And even more common in birds with once in every 1 764 births. Also, it is even more uncommon in the wild because the animals have almost 0% chance of survival from the sn and developing cancer, their predatos can pick them out muh easier an even some animals family ignore/shun them because they seem foreign to the rest of the members of that species.

media type="youtube" key="r4q4V2LbzD0" height="315" width="560" A video to help clear up what albinism is and what melanin does to protect us. Also, how a lack of melanin can affect us.

Finally this picture shows that if you do a dihybrid cross of this gene the children have 25% chance of getting albinism. So yes this gene can be inherited!

Additonal Sites: more about melanin [] how our body adapts to uv exposure [] [] [] Sources: [] [] [] []

=Wiki Post #3: Will Humans continue to evolve? May 16, 2013=

There has been debate that humans have stopped the process of evolution but there are different ways we will evolve and adapt in the future. However, will it be by means of natural selection or more so by artificial selection? Because we decide what we like in humans. Also, how will we evolve when another catastrophic event takes place on Earth, will we be able to adapt to the new environment?

Evolution of the american diet.

__Evolution:__ is the change in the inherited characteristics of biological populations over successive generations. Evolutionary processes give rise to diversity at every level of biological organisation, including species, individual organisms and molecules such as DNA and proteins. The key to evolution is variance in your offspring and the more offspring you have the higher the chance of natural selection selecting for a gene that is more advantageous.

Why has human evolution possibly stopped?
British geneticist Steve Jones thinks evolution for humans has stopped, at least slowed down, is because there are very few older men in society that reproduce. Sperm of older men carry many more mutations than those of younger men. Mutations in the sex cells and for the offspring give them genetic variations which is essential for natural selection to work which would mean a halt for our evolution. Jones thinks evolution and natural selection in humans stopped almost 10 000 years ago. Other arguments he and many people have towards the halt of our evolution is that it takes many generations for it to happen. So the faster the population matures and reproduces the faster we will see natural selection occurring. Because we have very few offspring and take a long time to mature we have decreased in genetic variance for natural selection to select from. Also, natural selection works for when organisms need to adapt to their environment because of selected pressures. As of right now humans have very few selected pressures and less so in North America so there is no need for us to adapt anymore.

However, natural selection is still occurring just like it would in nature. The stupid ones die off and selecting for the ones that are smart enough to stay out of harms way and survive.

Future Evolution of Humans:
Personally I don't think that evolution has stopped because our society is starting to regain biodiversity by blending cultures and races. If genetic variation is the key to evolution then white american's producing offspring with different races such as African, Chinese, Indian, Korean etc starts to create more variance once again maybe leading to a new mutation which enables further evolution. I also think it is good to gain more genetic variance as we can so that if a catastrophic event does occur we have a better chance of adapting to the new environment and surviving.

Predictions: media type="custom" key="23068118" A video briefly discussing natural selection, the evolution of humans, and how we can evolve physically, emotionally and intellectually.

Some traits that we may adapt in the future are:

-__Race differences will dissapear:__ Because there are no longer any populations that are isolated and that we are reproducing with different races in the future we will look a lot more similar, features and colour.

-__Lacking wisdom teeth:__ Because of evolution our jaw has gotten smaller in size because we no longer need to bite hard seeds or roots,etc and because of the shrinking there is not enough room for wisdom teeth to grow through. They are considered vestigial molars and in fact 35% of people are already born without wisdom teeth. Maybe it is happening already... Shows how our jaw is too crowded for wisdom teeth.

-__Less hair:__ Because we no longer need hair as an insulator to keep us warm it will start to diminish even more so than it already has compared to apes. However, artificial selection can occur here whether girls like guys who are hairy vs. hairless.

However, I still think that the biggest and most notable change humans can go through by natural selection is if our environment changes and we are face with new selected pressures. This includes us inhibiting or colonizing other planets such as Mars. This would create a new geographical isolation for speciation of humans to occur. In 2023 there is a space program called Mars One that is currently recruiting volunteers to attempt the first ever colonization of Mars. __To read more go to:__ [] Additional Sites: [] [] [] Resources: [] [] [] [] []

=Wikipost #4- The nervous system: The Brain= = = When you think of the nervous system, the first thing you usually think of is the brain. The truth is, it is not easy to make sense of the brain. It is known as the most complex organ in the human body. This one organ is responsible for our actions, memory, feelings, and how we experience and interact with the world.

Above is a false coloured MRI of the human brain. MRI's are used to look at the human brain without having to cut open the human brain. MRI's are use-full for locating things such as tumours, infections, and signs of a stroke.



The human brain can be divided into three main parts, as seen above. __**The** **Cerebrum**__ is the largest part of the brain, and is also known as the forebrain. Shown above the cerebrum is made of four different parts; the frontal lobe, The temporal lobe, the occipital lobe, and the parietal lobe. Each of these have there own responsibility. The cerebrum is responsible for cognitive and motor functions. This includes thought processing and walking. __**The** **Cerebellum**__ is a small part of the brain described as a walnut. it is responsible for motor coordination, posture and maintaining equilibrium. Damage to this part of the brain result in feeling dizzy, trouble standing and walking. __**The Brain Stem**__ is the area below the cerebellum and the cerebrum that connects the brain directly to the spinal cord. It is responsible for non-conscious movements, and reactions.

media type="youtube" key="9UukcdU258A" width="420" height="315"

This video shows the parts of the human brain, along with it's functions

Tasks your brain performs:
 * It controls body temperature, blood pressure, heart rate and breathing.
 * It accepts a flood of information about the world around you from your various senses (seeing, hearing, smelling, tasting and touching).
 * It handles your physical movement when walking, talking, standing or sitting.
 * It lets you think, dream, reason and experience emotions.

These tasks are performed by the brain through the nervous system and the endocrine system. Nervous system: Functions through the process of neuron firing when a stimuli or signal is received by another neuron or the environment. A neuron is composed of a cell body, dendrites, axon, axon terminal and myelin sheath.

The basic design of a neuron and its components.

Neurons transfer a signal or impulse from cell to cell through ion exchange that occurs at the nodes on the axon; whereas, the endocrine sends signals to all of the tissues at once by releasing chemicals called hormones into the bloodstream. Hormones are made in the hypothalamus, a gland in the middle of the brain, and it stores the hormones in the pituitary gland, also in the brain, where it will be released at a certain time. Endocrine system takes a lot longer to occur than the nervous system, minutes, hours, days or years. An example is puberty.

The 10 endocrine glands in the human body. However, every person only has 9.

Resources: [] [] [] [|http://www.livestrong.com/article/78174-three-parts-human-brain] []

Further Reading: [] [] [] []

=Wikipost #5: Endocrine system= "The Endocrine system is the bodily system that consists of the endocrine glands that releases their secretions (hormones) into the bloodstream to reach and act on target cells of specific organs."

The Endocrine system has 10 glands, and they are; 1.) Pituitary gland 2.) Pancreas 3.) Hypothalamus 4.) Thyroid gland 5.) Adrenal glands 6.) Pineal gland 7.) Thyroid 8.) Thymus 9.) Testes 10.) Ovaries

This picture just shows the 10 glands more clearly so you have an idea of where they are located. media type="youtube" key="WVrlHH14q3o" width="560" height="315"

=Endocrine System Diseases= The Endocrine System can develop certain diseases and in certain places, for example; Diabetes - This happens when the **pancreas** does not produce the right amount of insulin for the body to properly function. Insulin is very important for the body because it helps convert sugars and other nutrients into energy for the body. Osteoporosis - Is a disease where the bones become very brittle and are easier to break. This occurs for women when there is a decrease of the hormone estrogen, when happening during menopause. This can also happen to men when there is a decrease of testosterone happening when a male grows older.

Addison's - Addison's disease is when the adrenal glands produces a short amount of steroid hormones. This can be dangerous because the steroid hormones help many important functions like the levels of blood sugars, stress, helping with infections and keeping a normal sexual drive. The symptoms of Addison's disease may include; Thyroid Cancer - Thyroid cancer can take place if the cells that are in the thyroid grow and wont stop growing. This can cause two different types of tumors. Benign which are noncancerous tumors or malignant which are cancerous and if not removed within an amount of time can spread.
 * Low blood pressure
 * Pain (muscle, joints)
 * Weakness
 * Fatigue
 * Hands, neck and face start to darken

=FUN FACTS! =
 * Without the Pineal gland, we wouldn't be able to sleep that well, because it produces a hormone called Melatonin which helps with our sleep at night!
 * The Endocrine system is greatly responsible for your behavior (how you act) !
 * The Endocrine system is the reason we produce insulin!
 * The reason you feel things like hunger or thirst is because of your Hypothalamus!



Resources: [] //[]// //[]// [] [|www.youtube.com]

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