Hi List, I am looking for a good website that can explain really basic DNA to a beginner, including very basic stuff such as the fact that there are 4 letters (chemicals) that make up our DNA, and that the alteration of one of these "letters" is a mutation. I also want to explain basic Y DNA testing to this person. Any suggestions on a websites that would explain this stuff would be appreciated. Thank you. --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus