What is the role of the two original dna strands in replication?

When a cell divides, it is important that each daughter cell receives an identical copy of the DNA. ... This model for replication suggests that the two strands of the double helix separate during replication, and each strand serves as a template from which the new complementary strand is copied

To synthesise new DNA and RNA

Explanation:During replication, DNA strands are separated from each other by helicase enzyme. These two separated strands act as a template strand. From the template, new DNA strands synthesised in opposite directions.  The one strand synthesized continuously, called the leading strand and the other strand synthesized small fragments of DNA. This is a discontinuous process and the strand call lagging strand. The smaller fragments of DNA are called Okazaki fragments. The DNA polymerase adds new nucleotides and it is initiated by RNA primase in the template strands. This RNA primase later separates from the lagging strand and forms mRNA which comes to the cytoplasm from the nucleus. In this way, the original DNA strands form new DNA strands and the RNA.

step 1: initiation

initiation is the beginning of transcription. it occurs when the enzyme rna polymerase binds to a region of a gene called the promoter. this signals the dna to unwind so the enzyme can ‘‘read’’ the bases in one of the dna strands. the enzyme is now ready to make a strand of mrna with a complementary sequence of bases.

step 2: elongation

elongation is the addition of nucleotides to the mrna strand. rna polymerase reads the unwound dna strand and builds the mrna molecule, using complementary base pairs. there is a brief time during this process when the newly formed rna is bound to the unwound dna. during this process, an adenine (a) in the dna binds to an uracil (u) in the rna.

step 3: termination

termination is the ending of transcription, and occurs when rna polymerase crosses a stop (termination) sequence in the gene. the mrna strand is complete, and it detaches from dna.