what is a snp?
<answer> A single nucleotide that occurs at a specific position in the genome. <context> A single-nucleotide polymorphism, often abbreviated to SNP (/ˈsnɪp/; plural /ˈsnɪps/), is a variation in a single nucleotide that occurs at a specific position in the genome, where each variation is present to some appreciable degree within a population (e.g. > 1%).