2. A gene is a particular sequence (a string) of nucleotides on a particular site of a chromosome. It is made up of combinations of A, T, C, and G. These unique combinations code for a particular amino acid, much as letters join together to form words.

4. A chromosome is nature’s great packaging experiment – it contains tightly coiled DNA around special proteins. The DNA of a human being’s 23 chromosomes, when uncoiled, is 2 meters long!!

6. A genome is made up of all of the DNA in an organism’s chromosomes—it is all of its genetic information.

8.  An analogy to the human genome stored on DNA is that of instructions stored in a library.  The library would contain 46 books (chromosomes).  The books range in size from 400 to 3340 pages (genes), which is 48 to 250 million letters (A,C,G,T) per book.

9.  So, the library contains over six billion letters total;  The library fits into a cell nucleus the size of a pinpoint;  A copy of the library (all 46 books) is contained in almost every cell of our body.

10.  A 13-year project (1990-2003) that discovered all estimated 20,000 to 25,000 human genes.  The project also discovered the complete sequence of all 3 billion DNA bases (A,T,C,G).  All the information in stored in databases.

11.  Why bother? Just a few reasons….  Improved disease diagnosis  Determining genetic predisposition to disease  Developing gene therapy  Designing custom drugs