DNA+duplication

DNA Duplication or more correctly DNA Replication.

DNA strands are pulled apart starting at a point called the origin. This site is usually rich in AT bonds as these bonds only have 2 hydrogens as compared with 3 in GC bonding. Thus less energy is needed to start the separation. As the strands are unwound and pulled apart, various proteins etc build the missing side of the helix to create 2 new identical strands of DNA.

When the strands separate this forms RNA. In RNA the T base is replaced with different U base. Which on completion is replaced with a T base. So reading one side of the DNA as ACAGTC would become ACAGUC in the RNA.

[|More detail from wikipedia]