What is a possible variant for a characteristic referred to as?

The term that describes a possible variant for a characteristic is "allele." An allele refers to one of the different forms of a gene that can exist at a specific locus on a chromosome. For example, in the case of a gene that determines flower color in plants, the gene might have different alleles for red or white flowers. Each individual inherits one allele from each parent, and the combination of these alleles can influence specific traits seen in the organism.

The other terms relate to genetic characteristics but are not interchangeable with "allele." A trait is a specific characteristic or feature of an organism resulting from the interaction of its genotype with the environment. Genotype refers to the genetic makeup of an individual, essentially the specific alleles present, while phenotype is the observable physical or biochemical characteristics of an organism as determined by both its genotype and environmental factors.