Respuesta :
Answer:
Three proposed models: 1) Conservative
2) Semiconservative
3) Dispersive
Correct one: 2) Semiconservative
Explanation:
Meselson and Stahl proposed that the process of DNA replication could be conservative, semiconservative or dispersive. Conservative DNA replication will form one DNA duplex with both newly formed strands and the other duplex with both parental strands. The semi conservative mechanism will form two DNA helices each of which would have one parental strand and one newly formed strand (hybrid). The dispersive mechanism will form DNA double helices with patches of the new and parental strand.
However, they found that DNA replication follows a semi-conservative mechanism as after two rounds of replication of heavy chain DNA in the light-medium formed two molecules of hybrid DNA and two DNA molecules with light chains only. There was no DNA molecule with both the strands having the heavy chains.
