For other uses, see Transition. Definition of transitions and transversions. In genetics, a transition is a point mutation that changes a purine nucleotide to another purine (A â G) or a pyrimidine nucleotide to another pyrimidine (C â T).Approximately two out of three single nucleotide polymorphisms (SNPs) are transitions.Transitions can be caused by oxidative deamination and tautomerization.or other uses, see Transition. Definition of transitions and transversions. In genetics, a transition is a point mutation that changes a purine nucleotide to another purine (A â G) or a pyrimidine nucleotide to another pyrimidine (C â T).
fringe benefit - an incidental benefit awarded for certain types of employment (especially if it is regarded as a right); a limousine is one of the fringe benefits of the job. perk, perquisite. benefit - financial assistance in time of need.
Internal Revenue Code Section 132 provides eight types of fringe benefits that are excluded from gross income. These include fringe benefits which qualify as a no-additional-cost service, qualified employee discount, working condition fringe, de minimis fringe, qualified transportation fringe, qualified moving expense reimbursement, qualified retirement planning services, or qualified military base realignment and closure fringe.