DNA: The Secrets of Life DNA stands for deoxyribonucleic acid and holds all the genetic information of an organism. DNA: The Secrets of Life

DNA The two scientists credited with unraveling the structure of DNA are James Watson and Francis Crick. Every cell in your body contains DNA.

The DNA molecule can be compared to a ladder that has been twisted into a continuous spiral. The uprights of the twisted molecular ladder are all identical all along its length. However, the rungs vary in composition. Each individual rung pairs up just two of the following four chemicals: Guanine, Cytosine, Adenine, and Thiamine or G, C, A, and T, for short.

The arrangement of these four chemicals, G, C, A, and T, forms a code that cells can read. A segment of these letters represents the genetic code for a characteristic.

Chromosome: is the physical packaging of the DNA Chromosome: is the physical packaging of the DNA. Chromosomes occur in pairs. A gene is an uninterrupted segment of DNA, which contains coded instructions. Each member of a chromosome pair carries the same genes, but it could be a different version. Example at the same place on a chromosome is eye colour. On one chromosome it could be blue eye colour and on the other green. Because blue is dominant, that is the trait shown.

http://learn.genetics.utah.edu/units/basics/