DNA is a polymer made up of two strands that run side by side and twist into the famous double helix shape.

Basic answer

  • Normal DNA (the kind in human cells) consists of 2 strands, so it is called double-stranded DNA.
  • Each strand is a long chain (polymer) of repeating units called nucleotides.

Quick structure scoop

  • The two strands are called polynucleotides because they are long polymers of many nucleotides linked together.
  • These strands run in opposite directions (antiparallel) and are held together by hydrogen bonds between base pairs, forming the double helix.

TL;DR: DNA is a polymer made up of two strands.