RNA-DNA Hybrid
Where the helix is unwound, the coding strand consists of unpaired bases, whilst the template strand consists of an RNA:DNA composite, followed by a number of unpaired bases at the rear. This hybrid consists of the most-recently-added nucleotides of the RNA transcript, complementary base-paired to the template strand. The number of base-pairs in the hybrid is under investigation, but it has been suggested that the hybrid is formed from the last 10 nucleotides added (Griffiths, pp 259–265).
Read more about this topic: Coding Strand