Chromosome+2

=Chromosome #2= =**Size**=

Chromosome #2 contains more than 237 million base pairs and is the second largest chromosome found in humans. (http://www.nature.com/nature/journal/v434/n7034/full/nature03466.html, April 27, 2012) A base pair is a pair of nitrogenous bases joined together by the necessary amount of hydrogen bonds.



=**Excerpt from the book "Genome", by Matt Ridley**=

group of reptiles that almost went extinct 200 million years ago in competition with the better-designed dinosaurs. We are descend ed from limbed fishes, which almost went extinct 360 million years ago in competition with the better-designed ray-finned fishes. We are chordates, a phylum that survived the Cambrian era 500 million years ago by the skin of its teeth in competition with the brilliantly successful arthropods. Our ecological success came against humbling odds. (Ridley, 25-26) "
 * 1) "We are apes, a group that almost went extinct fifteen million years ago in competition wit the better-designed monkeys. We are primates, a group of mammals that almost went extinct forty-five million years ago in competition with the better-designed rodents. We are synapsid tetrapods, a

These two excerpts talk about the evolution of animals up until the humans, and the second excerpt plays a big factor in proving that humans evolved from a long line of animals up until apes. =Gene #1- LCT (Lactase)=
 * 1) "Chromosome 2, the second biggest of the human chromosomes, is in fact formed from the fusion of two medium-sized ape chromosomes, as can be seen from the pattern of black bands on the respective chromosomes."(Ridley, 24)

= =

Location of the gene Lactase
Lactase is a gene which resides on chromosome 2 and it is used for creating the enzyme lactase. This enzyme aids our body in the digestion of lactose, a sugar found in dairy products. Without this gene our body would not be able to make lactase, preventing us from



consuming lactose. (http://ghr.nlm.nih.gov/gene/LCT, April 28, 2012) If one did not have this gene he would become lactose intolerant. This means that he would not be able to consume lactose. This disability cannot be cured, however to get the calcium they need people consume things such as soy milk. =‍**Gene #2- TPO ( Thyroid Peroxidase )**=

The gene location is on chromosome 2

The thyroid peroxidase gene is a gene which is located on the second chromosome and provides the instructions to make an enzyme known as thyroid peroxidase. The enzyme is crucial to the thyroid gland and the process of making thyroid hormones. These hormones are important because they regulate growth, brain development, and our metabolism. Thus without this gene our bodies would not be able to properly function (http://ghr.nlm.nih.gov/gene/TPO, April 27,2012) If a mutation were to occur in the second chromosome ruining the TPO gene, then our body's different processes would not run properly.

=‍**Disorder: Hypothyroidism**=

Hypothyroidism is a disorder in which the thyroid gland does not produce enough thyroid hormones. When this happens the body is not able to properly grow and develop. Furthermore this disorder reduces the body's metabolism, the process in which the body eats, breathes, and regulates heat using energy.



This disease is inherited when the child receives a defective thyroid peroxidase gene (as discussed above) on chromosome 2. The defective gene may be caused due to three main things: Hypothyroidism is a very serious disorder, therefore the doctors diagnose a baby twenty four hours after their birth. They did this by taking blood from a baby's heel and testing it for low thyroid hormone levels or high thyroid stimulating hormone levels.
 * 1) an autoimmune disease attacks the thyroid gland
 * 2) surgery and radiation to treat thyroid cancer
 * 3) rare and random genetic events in which a mutation is acquired during early development.

Anyone of any age can receive hypothyroidism, although women ages sixty and older have the highest risk of receiving it. (http://www.webmd.com/a-to-z-guides/hypothyroidism-topic-overview, April 27,2012) This disorder displays many disorders in its victims depending on their ages. In babies who inherit this disorder it affects their growth and development. It causes mental retardation, delayed puberty, stunted growth, and the inability to coordinate muscle movements (known as ataxia). In adults it slows the body's metabolism causing them to feel sluggish mentally and physically. Symptoms also include weakness, fatigue, muscle aches, mood swings, hair loss, memory loss, or slow speech. Although the symptoms will progress if one does not receive medical attention, it is almost never life threatening. (http://www.endocrineweb.com/conditions/thyroid/hypothyroidism-too-little-thyroid-hormone, April 27, 2012 In order to treat your symptoms, one must receive hormone replacement therapy everyday. The synthetic hormones will reduce one's symptoms lessening the severity of the disorder. (http://learn.genetics.utah.edu/content/disorders/whataregd/hypothyroidism/index.html, April 28, 2012) =**‍_Fun Facts about Chromosome 2**=

1.This chromosome is the second largest chromosome. 2. Chromosome 2 was formed by the fusion of two mid-sized ape chromosomes.(Ridley, 24) This offers proof that we evolved from apes. 3.Chromosome 2 has 881 genes. (http://bioinfo.mc.vanderbilt.edu/SZGR/browseByChr.do?Chr=2, April 28,2012)

LCT - lactase - Genetics Home Reference. (n.d.). Genetics Home Reference - Your guide to understanding genetic conditions. Retrieved April 24, 2012, from @http://ghr.nlm.nih.gov/gene/LCT