Conservative replication dna strands were separating here and there and specifying the daughter sequences, but then the daughter sequences went out and made a brand new model. Dispersive replication dna unravels here and there; replication occurs here and there and then you end up with two daughter molecules that had some old and some new in no particular arrangement. Semiconservative replication each time dna replicates, one of the parental strands end up in the daughter molecule and the other strand is newly synthesized. Meselson stahl experiment: tried to prove semi-conservative replication, grew bacteria in the presence of heavy nitrogen so all dna was heavy, then they washed it out with light nitrogen and went to see if. Light at the top and heavy on the bottom, increasing in density. When you add dna, dna moves through the solution and then stops when the salt density is the same as the dna density.