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.
Go through them in the order given until you have an oxidation number assigned. 1  For atoms in their elemental form, the oxidation number is 0. 2  For ions, the oxidation number is equal to their charge. 3  For single hydrogen, the number is usually +1 but in some cases it is 4  -1. For oxygen, the number is usually  -2.