On the basis of mechanism of inheritance of enzymes in the pink bread mould Neurospora crassa Beadle and Tatum in 1941 gave one gene-one enzyme hypothesis. Watson and Crick (1953) proposed the double helical structure of DNA. The two strands of DNA are joined by hydrogen bonds. Temin and Baltimore discovered reverse transcription in retrovirus i.e., the synthesis of complementary DNA from single strand of RNA. This is also called feminism.