History of genetics of the fruit fly "Drosophila melanogaster". In 1928, Frederick Griffith showed that genes could be transferred. In what is now known as Griffith's experiment, injections into a mouse of a deadly strain of bacteria that had been heat-killed transferred genetic information to a safe strain of the same bacteria, killing the mouse. A series of subsequent discoveries led to the realization decades later that the genetic material is made of DNA (deoxyribonucleic acid). In 1941, George Wells Beadle and Edward Lawrie Tatum showed that mutations in genes caused errors in specific steps in metabolic pathways. This showed that specific genes
Isocyanic acid Isocyanic acid Isocyanic acid is a chemical compound with the formula HNCO, discovered in 1830 by Liebig and Wöhler. This colourless substance is volatile and poisonous, with a boiling point of 23.5 °C. Isocyanic acid is the simplest stable chemical compound that contains carbon, hydrogen, nitrogen, and oxygen, the four most commonly found elements in organic chemistry and biology. Isocyanic acid can be made by protonation of the cyanate anion, such as from salts like potassium cyanate, by either gaseous hydrogen chloride or acids such as oxalic acid. HNCO also can be made by the high-temperature thermal decomposition of cyanuric