Organellar genetics

Although most heritable traits in higher organisms are controlled by DNA (deoxyribonucleic acid) in the nucleus, there are now available, a fairly large number of examples where DNA located in cytoplasmic organelles is known to control hereditary traits. DNA was shown to be present in chloroplast (Ris and Plaut, 1962) as well as in mitochondria (Reich and Luck, 1966), and this led to the development of science of organellar genetics. There are a number of well established examples of organellar inheritance available now. Some of the important ones are discussed in this section.