Genetics
Mitochondria and chloroplasts carry some DNA of their own. Their make-up is decided by genes in the chromosomes and genes in the organelle. Carl Correns discovered an example in 1908. The four o'clock plant, Mirabilis jalapa, has leaves which may be white, green or variegated. Correns discovered the pollen had no influence on this inheritance. The colour is decided by genes in the chloroplasts.