16. The bar code of life.
The human genome contains about 30,000 genes.
To decipher the genetic code, the DNA in each gene is broken down into fragments and the sequence of the four components A, T, G and C in each fragment determined on sequencing gels.
The results from each fragment are combined to give the complete sequence of the gene. The patterns obtained on the sequencing gel resemble supermarket bar codes. DNA is the bar code of life.