Genome Chapter 4

Assignment:
Blog on your Fourth Chromosome


In chapter four of Genome, Matt Ridley talks about the most popular gene associated with disease, which is, Huntington's chorea.  Many people who don't actually have true knowledge on genes, immediately believe genes are on chromosomes to cause diseases.  Yet, this is not true at all.  For example, we all have the Wolf-Hirshhorn gene except, those that develop its syndrome is that their gene is missing all together.  In reality, diseases relating to the malfunction of genes get there name if that particular gene is missing in normal human bodies, not because the DNA is written differently.  One thing i found very interesting about Chromosome four is that it contains the word, CAG, being constantly repeated either 6 or 30 times.  "If the word is not repeated more than thirty times, you will be fine."  So if the repetition of CAG is redundant for a very long time, then as a result we can develop Huntington's Disease.  "The more glutamines there are at this point, the earlier in life the disease begins."  Huntington's Disease can start to develop as early as when you are thirty or fifty years of age.  Affected Fathers are most likely to give their son's this disease "more severely and at a younger age because their sperm cell's CAG are growing.  I also find it very interesting that other chromosomes also share the C*G repeats' that cause neurological diseases in a human.  For example, myotonic dystrophy is caused by the repetition of GTG in a gene on chromosome nineteen.  This is the main thing I learned from this chromosome.  Now I know why the author titled this chapter "FATE" because "your fate is in your genes."  It does not matter if you live in a world of riches or even if you maintain a well balanced diet,  you can develop a disease if your genes feel like it or not.

Genome Chapter 3

Assignment
Do Blog on Third Chromosome

In Chapter 3 of Genome Matt Ridley talks about the history of the third chromosome of the human body.  Chromosome three happens to have a "paragraph of DNA letters that shares 52% of its letters with the fungal gene : homogentisate."  This boring gene was found after modern genetics had begun, around 1960's.  When scientists had discovered the rare yet not deadly disease, Alkaptonuria it had laid untouched for many years.  Yet during the 1990's two Spaniards decided to take a closer look on this disease which led tho their discovery that the mutant had "a defective version of the protein called homogentisate dioxygenase."  The similar humane gene that they found was on the arm of chromosome three.  Matt Ridley describes this chromosome as "the epitome of a boring gene, causing a  boring disease when broken" Yet I disagree with him.  I believe this chromosome is unique because unlike the other chromosomes in the human body, this chromosome does not cause a malfunction in the body while other chromosomes do.  For example, even if its lettering somehow got mixed up in order it will not cause the death of a person and the gene is shared by every animal in this world. It follows the law of dominance.  Maybe chromosome number three might not be as fancy as chromosome one and two, yet it is still part of us and does the same job for every creature in this world.
  

Blog 4 Nephron

BOW Describe how a nephron works. How is this similar to counter currents or hydrostatic skeletons?

The nephron is the basic part of the kidney.  It removes excess water, wastes, and other substances from your blood.  Sodium, potassium or phosphorus are returned whenever they run low in the body.  The parts of the nephron are the Bowman's capsule that is located in the cortex. Next to it is a twisted region is the proximal tube.  After this tube is the loop of Henle, it extends from the cortex down the medulla and back.  The second twisted region of the nephron is called the distal tubule, located in the cortex as well.  The collecting dust is the open end of the nephron that extends from the cortex all the way through the medulla.  The kidney regulates the blood in the three processes.  First it filters 20%  of the plasma from the blood into inside of the nephron.  Next, it reabsorbs the items the body needs from the lumen back into the blood.  Lastly it secretes some unwanted items from the blood into the lumen of the nephron.  The counter current in the kidney occurs in the loop of henle.  The contercurrent flow is similar to the nephron because it works with water as well. The main difference is that counter currents allow water to be reabsorbed into the body while the nephron works to remove the excess water brought in the kidney by the counter currents.


http://science.howstuffworks.com/environmental/life/human-biology/kidney.htm
http://www.shodor.org/master/biomed/physio/dialysis/kidney.htm
http://www.renalinfo.com/us/how_kidneys_work_and_fail/kidney_functions/index.html

Kidney Functions Mindmap

Genome Chapter 2

ASSIGNMENT:

Blog on your second chromosome

In chapter two of Genome, Mark Ridley talks about chromosome 2, the second largest chromosome in the human body.  He also explains how before the 1950's, every scientist believed that every human had 24-pairs of chromosomes.  It wasn't until the Indonesian, Joe-Hin Tigo revealed his discovery on how chromosome two is actually a fusion of two medium-sized ape chromosomes.  Mostly everyone in the world has been told that their ancestors are chimpanzees, but is this theory actually provable?  Scientists believe that at one point, "about ten million years ago, there probably lived at least two species of ape in Africa, which gave rise to the human beings and the chimpanzees."  Humans share 98% sequence of DNA, the immune, digestive, vascular, lymph, and nervous system with chimpanzees!   I find it amusing that the only difference between us is our appearance.   Even the human brain is similarly structured as a chimpanzees'.  As Mark Ridley explains, "the missing link was probably a forest creature...at some point, its population had split in half."  This is one of the many reasonable hypothesis scientists agree upon because, "the separation of two parts of a population is often the event that sparks speciation."  Natural disasters of maybe even the formation of the Sahara dessert had caused these two species of apes to drift apart or be isolated from each other and develop there own separate genes, one of which happened to be of humans.   Even after scientists had concluded, "the differences between human beings and chimpanzees are genetic differences and virtually nothing else," there are thousands of people that still deny this "fact".  In my opinion, I do think there is reasonable evidence to say chimpanzees have a part in the evolution of humans but i also think everyone's thoughts on this theory should be respected.

Chapter 1 Genome

ASSIGNMENT: Read Genome Do Blog 1

In chapter one Matt Ridley explains how the discovery of the gene was not founded by physics, chemistry scientists but instead it was explained by biology.  "Every chromosome has a long arm and a short arm separated by a pinch point known as a centromere"  On chromosome, there is a repeating sequence of A's, C's, G's and T's making up a 120 letter paragraph.  This paragraph is the most active gene in the human body and is copied into RNA.  It resided with other proteins and RNA's.  "Protein represents chemistry, living, breathing, metabolism and behavior aka phenotype".  DNA represents information, replication, breeding, sex aka genotype"  I find this statement very interesting because in the early 1940's no one actually understood the full functions or even meaning of the gene.  It's an astonishment how much information biologists have gathered just with one simple discovery of the gene.  Proteins and DNA can not live without one another.  They are dependent on each other in order for them to function properly.  In this chapter I also learned about the genome.  The genome is "the unity of life and the chemistry of the very earliest life on the planet."  This quote makes me think that the genome unites the three main studies of science which are Physics, Chemistry and of course Biology.  The genome plays an important role in all three sciences and our everyday lives.

Blog 3 Starfish

On our blog describe a starfish in terms of summetry, germ cell layers, coelem, Circulatory system, reproduction, feeding, excretion and nervous system. Find picture examples of each living class Crinoidea, Ophiocistioidea, Astroidea, Echinoiudea and Holothuoidea.

The echinoderms have radial symmetry, which means it has 5 or more arms.  A starfish has two cell layers, making them diploblastic. Germ layers are the primary tissue layers in starfish.  The coelem is the body cavity of a starfish that forms in the last stage of sea star development.  Circulation occurs in the coelem,  vascular system,  and the hemal system.  The hemal system is mostly organized to distribute nutrients in the digestive tract.  Starfish can either undergo asexual or sexual reproduction.  Fertilization takes place externally, and the fertilized embryos become part of zooplankton.  If they reproduce asexually, they undergo fragmentation.  Starfish feed on mussles. Their waste is excreted either through the anus(if present) or else through the mouth.  Echinoderms do not have a  real brain, instead they have a network of interlacing nerves, which is underneath the skin.  The ring nerves and radial nerves  of a starfish balance directional systems.

          Crinoidea

Ophiocistioidea



Astroidea



 Echinoiudea



Holothuoidea