The concept of inheritance takes shape: The road to understanding genetic engineering is paved with DNA

Everything we are is determined by the genetic information we carry. Forays into conquering disease and birth defects depend on understanding genes first. Through the millenia man has known that certain characteristics can be inherited. However, just what and where these genes were remained a mystery until the experiments of Avery, MacLeod, and McCarty (1944) revealed that a polymer called deoxyribonucleic acid (DNA) was in fact the genetic material responsible.