Troy+P.

=Wikipost 1: Genetics: March 25, 2013=

Down Syndrome, also known as trisomy 21, is the most common chromosomal condition known to humans. This abnormality is caused by the presence of an extra copy of chromosome 21. While most humans are born with 46 chromosomes, a baby diagnosed with DS has 47. The result of this extra copy causes a delay in the growth of a child both mentally and physically. This is caused by an error in cell division known as nondisjunction, which occurs at conception.


 * This picture is a study of chromosomes providing a visual display of the chromosomes grouped by their number, size and shape. This is known as a karyotype and is used to diagnose Down Syndrome.

Effects on the child:
The most notable and immediate way to identify Down Syndrome is through physical appearance. Often times, children with DS tend to share certain features such as a flat facial profile, an upward slant to the eyes, and a protruding tongue. Another physical trait found among people with Down Syndrome is low muscle tone or "hypotonia". This trait leads to a slower rate of growth and also many feeding and digestive issues. Mentally, this condition drastically slows down the learning process among the child. Most notably a delay in cognitive development with specific deficits in speech, language and auditory short term memory. Although intellectual impairment, children with DS will eventually develop normal skills throughout their lives with the help of speech and developmental therapies provided at a young age.


 * This is a photo of a three month old baby diagnosed with Down Syndrome and also a full grown adult with Down Syndrome.
 * Note the physical features such as a flat facial profile and an upward slant to the eyes.

Health Issues:
Many health complications occur along with this condition. It is estimated that 40% of children with Down Syndrome will eventually encounter some form of congenital heart defects. Along with an increased risk of pulmonary hypertension, a disease that leads to lung damage, people with DS are also much more susceptible to hearing and vision difficulty. Hearing loss is a result of fluid buildup in the inner ear or structural problems to the ear itself. Vision difficulty can include strabismus and an increased risk of cataracts. It is required to have an echocardiogram performed on new born babies to identify any serious cardiac conditions. Despite these health issues, people with Down Syndrome can lead very healthy lives with medical aid. Their average life expectancy is 55, however, many live to be well into their 60s and 70s.

**Facts:**
 * Down Syndrome is named after John Langdon Down, a British doctor who first studied and described the condition in 1887.
 * It wasn't discovered until 1959 that an extra chromosome was the cause of this condition.
 * Women age 35 and older have a significantly higher risk of having a child with DS.
 * Down syndrome occurs before conception; there is nothing a person did, or didn't do, to cause it.
 * There are three types of Down Syndrome:
 * 1) Nondisjunction: Third copy of chromosome in every cell. (95% of cases)
 * 2) Mosaicism: Only certain cells have extra third copy. (1-2% of cases)
 * 3) Translocation: Chromosome 21 is attached to another chromosome. (2-3% of cases)




 * This is a photo of John Langdon Down, a British doctor who first identified the condition in 1887. Down Syndrome is named after John Down.

Learning About Down Syndrome:
media type="youtube" key="o4y0k7zRGQw" height="315" width="420"

Further Reading:
http://www.nads.org/pages_new/facts.html This site briefly describes and explains Pre-Natal Diagnosis. http://kidshealth.org/parent/medical/genetic/down_syndrome.html# This site provides a simple explanation of Down Syndrome. http://www.down-syndrome.org/reports/313/ This site describes in detail the mental difficulties involved with Down Syndrome. http://www.down-syndrome.org/perspectives/94/ The story of John Langdon Down's journey with the discovery of Down Syndrome.

Sources Cited:
http://www.nads.org/pages_new/facts.html http://www.down-syndrome.org/reports/313/ http://www.medicinenet.com/down_syndrome/article.htm http://www.bbc.co.uk/health/physical_health/conditions/downssyndrome1.shtml

=Wikipost #2: Evolution (Charles Darwin): April 10, 2013=

Human evolution is one of the most complex and intriguing concepts in our current society. This topic is often portrayed as very controversial, however all theories must been taken into consideration to fully understand this process. The theory mainly emphasized in this wiki post will be the work of Charles Darwin.

Charles Darwin:
Charles Robert Darwin was a British scientist who based the foundations of the theory of evolution and influenced the way we think of the natural world. He was born February 12, 1809 in Shrewsbury, Shropshire. The Darwin family was known for their close relationships amongst themselves and also their wealth. Charles studied at Edinburgh University with aspirations to follow a medical career, however eventually transferred to Cambridge where he would join a five year scientific expedition on the survey ship HMS Beagle. Upon his trip, Darwin read Lyell's "Principles of Geology", which suggested that fossil found in rocks were evidence of life from thousands to millions of years ago. This contradicted current religious theories which sparked interest in the topic for Darwin. This is a photo of Charles Robert Darwin, a British scientist that revolutionized the theory of evolution.

Charles Darwin's Theory of Evolution:
After interest in the subject of evolution, Darwin began noticing key elements to the topic upon his trip on the HMS Beagle. While on the Galapagos Islands, Charles noted that each island had a type of bird (finch) which appeared closely related, however different in certain ways. After his return to England, Darwin began researching this connection among the bird, with interest of how others species may also evolve. Charles Darwin eventually devoted his life to this study. With the help of another naturalist, Alfred Russel Wallace, who had similar theories as Darwin, the two published a novel, "On the Origin of Species by Means of Natural Selection", in 1859. This novel became a huge topic of discussion among scientific world and also society in general due to it's controversial material. The novel claimed that //homo sapiens// were simply another form of animal and had evolved from apes. This theory immediately received negative feedback and attacks specifically from the Church. Although first doubted, Charles Darwin's Theory of Evolution soon gained credit and eventually became a very respected, well known theory amongst the natural world. Darwin died on April 19, 1882.




 * This photo shows the map of the HMS Beagle's voyage. It was in the Galapagos Islands that Darwin noted his first encounter with the theory of evolution through the similar connections amongst the birds of the islands.


 * This photo indicates Darwin's theory of human evolution, the main focus of this theory was that humans evolved from apes.This theory received very negative feedback and critism as it contradicts the Bible and God creating the world in seven days. Darwin's theory was published during very religious times, however was quickly orthodox as a valid theory.


 * This is a photo of Alfred Russel Wallace, a scientist and naturalist that helped Darwin create the theory of human evolution.

History of Charles Darwin:
media type="youtube" key="XKnqj3YFXU8" height="315" width="560"

Further Reading:
[] This website goes into great detail of the Darwin's Theory of Evolution. [] This website describes the voyage on the HMS Beagle. [] This site describes Alfred Russel Wallace's contribution to the theory. [] Biography of Charles Darwin.

Sources Cited:
[] [] [] []

=Wikipost #3: The Evolution of Dogs : May 22, 2013=

Although most of us only view our lovely pups as man's bestfriend, it is often times diffcult to remember that they are animals, specifically a subspecies of the gray wolf, a member of the Canidae family and also of the mammalian order, Carnivora. Therefore, when it is put into more logical terms, how did we domesticate a wild animal?

The comparison between a wild gray wolf and a cute pooch. Clearly a very drastic change between the two, over the course of generations.

Domestication:
Considering Gray Wolves are known as very aggressive and pack oriented, it made early domestication very difficult, however as evolution began to arise, the wolves would eventually realize that humans are the dominant figure amongst the species. This influenced some of the more tame wolves to develop obedience. Other important domesticated traits mostly come from artificial selection, or selective breeding, and also natural selection.

__Artificial Selection:__

Traits of artificial selection are influenced by the human breeder of the animal. These traits are most commonly influenced simply for the appearance of the dog, and not necessarily for beneficial use.




 * This is a prime example of artificial selection. These dogs were bred for a specific trait, whether it be fluffy fur, floppy ears or even size, regardless of the potential physical harm and side effects it may have on the animal. This type of danger often occurs amongst purebred dogs.

__Natural Selection:__

Naturally acquired traits are influenced through use and disuse over many generations. These traits are required to serve a purpose for the dog, such as physical or behavioral change. This can be caused by environmental change, reproductive use or survival.




 * This is an example of the original canine, the Gray Wolf. Many of the traits of this animal are influenced by environment and survival tactics, unlike it's current ancestor who has under gone selective breeding for a certain appearance. The Gray Wolf is very aggressive and adjusted to hunting techniques, unlike today's chihuahua for example.

Chihuahua:

 * Small, fragile, cute body.

living space.
 * They can exercise in 800 square feet

> Patellar Luxation: Knee cap can slide in and out of tendon, causing discomfort.
 * Very loving and devoted to owner.
 * Molera on skull (soft spot).
 * Life expectancy: 11-20 years



Gray Wolf:

 * Hunts in packs, 4-7 others on average.
 * Choose den sites and establish pack territory.
 * Not domesticated at all: Very dangerous.
 * Diet consists of goat, sheep, deer and moose.
 * Consumes 20 pounds of meat in one meal.
 * Life expectancy: 10-18 years (varying)

From Wolf to Dog: How did it happen?
This video goes into great detail on the evolution of dogs, as they started as carnivorous predators roaming, to domesticated house pets.

media type="youtube" key="heMftb760vs" width="420" height="315"

Further Reading:
[] Evolution of dogs. [] Examples of artificial selection. [] More on Gray Wolves. [] Prehistoric dogs.

Sources Cited:
[] [] [] []

=Wikipost #4: Genetics (Obesity): June 11, 2013=

It is one of the largest problems in today's society. Research shows that in the US alone obesity related illnesses claim over 850 lives a day and over 300 000 lives each year. Worldwide obesity has sky rocketed since 1980. In 2008, more than 1.4 billion adults have been deemed overweight. Of these, over 200 million men and nearly 300 million women are obese. Is this epidemic all caused by genetics or is it something more?

Obesity is a complex disease resulting from the interactions of a wide variety of hereditary and environmental factors. Obesity risk is two to eight times higher for a person with a family history as opposed to a person with no family history of obesity, and an even higher risk is observed in cases of severe obesity. Heritability of obesity may vary, however it tends to be higher for genes linked to adipose tissue distribution and for body fat excess. Weight gain and adiposity increase with age, an effect also influenced by heredity. Studies have shown that g enetic changes in human populations occur too slowly to be responsible for the obesity epidemic. However, how people respond to the same environment suggests that genes do play a role in the development of obesity.

children are obese in America.
 * A very obese boy flexing for the camera. More than one third of


 * Factors causing obesity through genetics: **

Although there are no specific genes involved with obesity, there are many different mental aspects that can be controlled or abused, depending on your genetics/inheritance. For example,  the drive to overeat (poor regulation of appetite and satiety); the tendency to be sedentary (physically inactive); a diminished ability to use dietary fats as fuel; and an enlarged, easily stimulated capacity to store body fat. Age is another varying aspect with obesity as seniors have a tendency to become obese due to lack of physical activity.

and women, also including age as a factor.
 * This is a chart comparing obesity rates amongst men

Controllable Factors:
Although genetics have a very small role in the obesity epidemic, it is proven that environmental factors and prevention are the key to avoiding obesity.

If you eat high-calorie, low-nutrient foods, you are likely to eat more calories than you burn each day, thus increasing your risk of becoming obese. Another risk factor is eating after you are full and eating quickly. Ex: Alcoholic beverages (9kcal/g), sugary beverages (pop, juices, energy drinks), animals fats.
 * Poor Diet:**



This is a photo of McDonald's Big Mac,containing 600 beverages. An excessive amount of sugar can lead to diseases such as obesity and diabetes.
 * This photo shows the amount of sugar in each of these calories, and 55% of your daily fats.

Lack of Physical Activity
If you don't get enough physical activity, you are likely to burn fewer calories than you eat each day, thus increasing your risk of becoming obese. For children, too little exercise and spending too much time watching TV or playing on the computer can increase their risk of gaining weight and becoming obese.

Age
The incidence of obesity more than doubles between the ages of 20 and 55, this may be related to a decrease in activity levels. A recent study found that within 30 years, over half of a large group of normal-weight men and women became overweight.

Video:
media type="youtube" key="a6bqwBs8HKA" width="420" height="315"

Further Reading:
[] Obesity amongst children [] Obesity prevention [] Causes Symptoms and treatment [] Obesity amongst our pets

Sources Cited:
[] [] [] []

=Wikipost #4: Dynamic Equilibrium (Endocrine/Exocrine): June 13, 2013=

Endocrine System:
The endocrine system is a unit of glands that secrete hormones into the bloodstream to maintain homeostasis. Endo, meaning inside, and crine (crinis) meaning secrete, this system is responsible for sending signals throughout the body, similar to the nervous system however the endocrine system takes much longer and the effects are very different. The main thing to know about the endocrine glands is that, unlike the exocrine glands, there are no ducts for secretions. They store the secreted hormones in intracellular vacuoles or granules. Organs such as the liver, kidney, heart and gonads have secondary endocrine functions. An example of this is the kidney that secretes hormones such as erythropoietin and renin. This photo demonstrates the many different glands involved with the endocrine system.

Endocrine Glands:
The endocrine glands secrete their hormones, directly into the blood rather than through a duct. The main endocrine glands include the pituitary gland, pancreas, ovaries, testes, thyroid gland, and adrenal glands. The hypothalamus is major and very important organ to the endocrine system. Other very important features of the body which are not so well known for their endocrine activity include the stomach, which produces hormones such as ghrelin (determining our hunger).

Exocrine Glands:
Exocrine glands are very different in comparison to the endocrine glands as they secrete hormones to body cavities or surfaces through the use of ducts.

Exocrine glands are named "apocrine" glands, "holocrine" glands, or "merocrine" glands based the method of secretion.
 * Apocrine glands - a part of the plasma membrane forms off the cell, containing the hormone.
 * Holocrine glands - the entire cell disintegrates to excrete the hormone.
 * Merocrine glands - cells excrete their substances by exocytosis.

Other great examples of exocrine glands include: Sweat ducts and tear ducts. An image of the sweat gland and the sweat pore An image of the anatomy of our eye and the tear duct (duct) where the hormone is released on the excretion. body surface.

Summary comparison:
Endocrine Gland:
 * Secretes hormones through the bloodstream, no use of ducts. Ex: Pituitary Gland

Exocrine Gland:
 * Secretes hormones onto body surfaces/cavities through the use of ducts. Ex: Tear/sweat Glands

This image compares exocrine glands with endocrine glands. Note the ducts (exocrine) and the capillary network (endocrine).

Understanding the Endocrine System:
media type="youtube" key="-S_vQZDH9hY" width="560" height="315"

Further Reading:
[] Endocrine System continued [] Endocrine System diagram [] Exocrine Glands explained [] Exocrine Diagram

Sources Cited:
[] [] [] []