Complex sentence: This is DNA which contains units named genes from which Messenger RNA is derived, that can produce proteins through a code (genetic code) in which a series of triplets (codons) of four possible nucleotides are generally translated into one of twenty possible amino acids.
Split into simpler sentences: This is DNA, which contains units named genes from which Messenger RNA is derived. This in turn produces proteins through a code (genetic code) in which a series of triplets (codons) of four possible nucleotides can be translated into one of twenty possible amino acids.