Afamous experiment, matthew meselson and franklin stahl grew e. coli cells in a medium containing only the "heavy" isotope or nitrogen, ^15n. these cells were then transferred to a medium with the "light" isotope of nitrogen, ^14n. the results of the experiment supported the hypothesis of semi conservative replication, which was proposed by watson and crick. heavy dna (^15n dna), hybrid dna, and light dna (^14n dna) can be separated by centrifugation. if cells containing ^15n dna are transferred to a medium with only ^14n nh_4ci as a nitrogen source, what percent of daughter molecules are composed of hybrid dna after 3 generations? predict what percent of daughter molecules would be composed of hybrid dna if dna exhibited conservative replication -that is, if a daughter dna molecule were composed of newly synthesized dna only.