7.1 dna & replication from Bob Smullen
Find a video lesson on this sub-topic at Dan Rott videos.
How DNA is packaged (1m 43s):
Here are some fantastic animated tutorials from McGraw Hill Education – DNA Replication (in prokaryotes) and DNA Replication fork.
HL Replication in a 5m video: Protein Synthesis.
Paul Andersen describes the molecular structure of DNA in What is DNA?. And here, he explains DNA Replication:
Here’s a TED-Ed lesson on what happens when your DNA is damaged.