A short sequence deoxyribonucleic acid (DNA) that is paired with one strand of the template DNA. It is the growing end of the DNA chain and it simply provides a free 3 ‘—OH end at which the enzyme DNA polymerase adds on deoxyribonucleotide units (monomers). Which deoxyribonucleotide is added is dictated by base pairing to the template DNA chain. Without a DNA primer sequence a new DNA chain cannot form since DNA polymerase is not able to initiate DNA chains.
A sequence of nucleotides that starts the replication or transcription of a gene.