Hybrid DNA and Semi-Conservative Replication — NEET Biology

Which of the following statements accurately describes the expected outcomes of different hypothetical DNA replication models in the context of Meselson and Stahl's experiment, or the actual findings, are NOT correct? S1: In the semi-conservative mode of replication, after one generation of E. coli grown in 14N medium following initial growth in 15N, all DNA molecules would be of intermediate density. S2: If DNA replication were conservative, the DNA extracted after two generations in 14N medium would yield three distinct bands: heavy, hybrid, and light density DNA. S3: Had DNA replication been dispersive, then after two generations of E. coli in 14N medium, all DNA molecules would appear as a single band with an intermediate density, progressively lighter than the first generation. S4: The observation of equal amounts of hybrid and light DNA after the second generation in 14N medium provided evidence consistent with a conservative mode of DNA replication. S5: The initial growth of E. coli solely in a 15N medium ensured that all parental DNA had a uniformly heavy density.