Dna bonds are held together by the hydrogen bonds and no covalent bonds because it would take a lot more energy to break the bonds to undergo replication. Millions and billions in a base pair that has to get into a 6um diameter nucleus. Histones get bundled together wraps a linker around it and then the histone wrap around each other called solenoid. Circular genome of prokaryotes is replicated from a single point of origin. Eukaryotes there can be multiple simultaneous replication forks. Separate the dna and replicate on both sides of the strain 5" to 3" on one side and 3" to 5" on another side. Single stranded binding proteins come onto the parental strand to keep it from coiling again. Dna girase cuts between nuclitides to relieve tension. Dna polyamerase 3 will make a complimentary strand at the origin only if it has a double strand.