1 a mutation occurring in a somatic cell, resulting in a change in the morphology or some other aspect of one part of an organism (usually a plant). 2  It may be maintained by vegetative propagation but not by sexual reproduction.oun. 1  a mutation occurring in a somatic cell, resulting in a change in the morphology or some other aspect of one part of an organism (usually a plant). 2  It may be maintained by vegetative propagation but not by sexual reproduction.
Although oxidation reactions are commonly associated with the formation of oxides from oxygen molecules, oxygen is not necessarily included in such reactions, as other chemical species can serve the same function. The reaction can occur relatively slowly, as in the case of rust, or more quickly, as in the case of fire.
Though [4Fe-4S] clusters typically function as part of elaborate electron transport chain, aconitase is unique in that instead of facilitating a long electron transport chain, it seems to use the electron density of the delocalized cluster to help coax the stereospecific change of citrate.