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.
Â§1.61-21(b) The taxable amount of a benefit is reduced by any amount paid by or for the employee. For example, an employee has a taxable fringe benefit with a fair market value of $3.00 per day. If the employee pays $1.00 per day for the benefit, the taxable fringe benefit is $2.00 per day. Special valuation rules apply for certain fringe benefits.