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.
To find the oxidation number of sulfur, it is simply a matter of using the formula SO2 and writing the oxidation numbers as S = (x) and O2 = 2(-2) = -4. Using the rule and adding the oxidation numbers in the compound, the equation becomes x +(-4 ) = 0. Solving for x, it is evident that the oxidation number for sulfur is +4. In chemical compounds, an atom's oxidation number refers to the charge that atoms have if the compound consists of only ions. When writing compound formulas or reactions, there are rules used to assign oxidation numbers.