Nova-+Genome+Summary

You may also search for this animation/presentation on Nova Online

//" This exploration allows you to travel to the tiny world of DNA. Beginning with the body and ending with the atoms that make up a single DNA base, you'll be able to zoom in to 15 different levels to see DNA's relationship to us as a whole. Along the way you'll also see the intricate bending and winding that takes place within a chromosome, which allows more than five feet of DNA to fit within the nucleus of a tiny cell!"// This is the description given by the author of this web page, Rick Groleau, and it essentially hits the nail on the head (metaphorically, of course!) about the effectiveness of this animation about the human genome. It takes you, step-by-step, on an in-depth journey, which explores the various details of the Human genome

The typical human body consists of over 100 trillion cells, each containing a seemingly never-ending chain of approximately three billion base sequences (excluding red blood, who lack nuclei and nuclear DNA) that make up the human genome. The DNA shared by these cells is identical, but the various cells of our body function very differently because the differentiation of these cells during embryonic development.This results from the expression of only parts of the human genome based on what cell it is. The human genome is comprised of two sets of 23 chromosomes, thus humans have a diploid number of 46 chromosomes. The genome consists of around 70,000 genes (Scientists have probably found an alternative number), but this only makes up less than 3% of the entire genome. The rest is known as intronic DNA as it does not code for any protein and possess some unknown function.

The genes are located on chromosome pairs on bands known as loci. In each of these loci, DNA bends and loops around to make itself more compact and fit in the confines of the nucleus of a given cell. A major type of DNA loop is a relatively thicker coil called a chromatin loop. These DNA loops are supported by protein that DNA segments associated with called histones. They attract because of their differences in the electrical charge of the molecules. (DNA molecules possess a slight negative charge while histones carry a slight positive charge) When DNA segments associate around many histones, the new complex created is called a nucleosome. Digging deeper, the double helix can be seen. This model was created by James Watson and Francis Crick, with the help of Rosalind Franklin's X-ray diffraction photos of DNA. This ladder-like structure is held together by nitrogenous bases that are held together by multiple hydrogen bonds. Each part of the DNA ladder's backbone is made up of a phosphate-sugar-base combination called a nucleotide, resulting in the creation of a longer polymer. Each nucleotide is made up of about 30 different atoms, primarily carbon and hydrogen.

The Human genome was able to be documented by scientists through the Human Genome Project, which is said to have reached completion in 2003. They have determined the base sequences, but there is still more research to be done to understand the meaning and function of these base sequences. All of this interacts to code for a human, including all the differences that we can easily observe. See also: Wiki page on DNA, Readings: James Watson, "The Human Genome Project: Past, Present, and Future" (1990); Robert Wright, "Achilles' Helix" (1990); and Elizabeth Pennisi, "Finally the book of life and the instructions for navigating it" (2000), in History 338 Reader; and David Baltimore, "Our Genome Unveiled," at [|http://www.nature.com/cgitaf/DynaPage.taf?file=/nature/journal/v409/n6822/full/409814a0_fs.html]