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The ABC’s of DNA — SNPs

illustration of DNA sequences forming the ladder rungs.

SNPs There are two main ways that people are genetically different from each other. Either they vary because they have a variation in the sequence of bases along their chromosomes. Or they differ because they have a different number of copies of a gene. It is the former situation we’ll discuss here, where the SNPs vary. A SNP, pronounced snip, is shorthand for single nulceotide polymorphism. A nucleotide is a genetic base — Adenine (A), Guanine (G), Cytosine (C) or Thymine (T) — attached to a sugar-phosphate molecule. Together the sugar and base form the backbone of a DNA molecule. … more…