$$ extbf{Explanation:}$$ $$ullet$$ In the denaturation step, the target DNA is heated to a high temperature (usually $$94^0$$C), resulting in the separation of the two strands.  $$ullet$$ Each single strand of the target DNA then acts as a template for DNA synthesis. $$ullet$$ During PCR if the initial denaturation step is missed, the dsDNA for which the polymerization process has to be done will not split into two template strands, and as a result primer annealing would not occur. Consequently extension would also not take place and we would not observe amplification of DNA.