Genetics. deoxyribonucleic acid: an
extremely long macromolecule that is the
main component of chromosomes and is
the material that transfers genetic
characteristics in all life forms,
constructed of two nucleotide strands
coiled around each other in a ladderlike
arrangement with the sidepieces
composed of alternating phosphate and
deoxyribose units and the rungs composed
of the purine and pyrimidine bases
adenine, guanine, cytosine, and thymine:
the genetic information of DNA is encoded
in the sequence of the bases and is
transcribed as the strands unwind and
replicate.
