Experiment by Meselson and Stahl in E. coli proved that DNA replication process is semi conservative.

François Jacob with Jacques Monod originated the idea that enzyme level regulation in cells occurs via regulation of transcription. They gave the operon model of gene regulation by studying the lac operon.

Hershey and Chase experiment concluded that DNA is the genetic material and not protein. Transduction experiments were carried out in their study where a bacteria was infected by a bacteriophage.

Maurice Wilkins and Rosalind Franklin made crucial contributions to the discovery of DNA's structure and provided data about its structure via X-ray diffraction images.

The one gene-one enzyme hypothesis given by Beadle and Tatum is a proposition that genes expression via the synthesis of enzymes, where each gene is responsible for producing a single enzyme that in influences a single step in a metabolic pathway of the cell.