Chromosomes
Inside each cell in your body are little x-shaped structures, made of DNA… the directions for how your body will grow! Learn more about chromosomes…
http://www.genome.gov/26524120
http://ghr.nlm.nih.gov/chromosomes
http://learn.genetics.utah.edu/content/begin/traits/
http://www.ornl.gov/sci/techresources/Human_Genome/launchpad/