半保留复制 semiconservative replication Parent 40440HH4 HOHH044HO 亲代 Parental strand Parental strand 40440HH40 HOHHO4HO 子代 40440HH4 HOHH O44H U Daughter strands半保留复制 semiconservative replication A G A A C T T A G T C T T G A A T C A G A A C T T A G T C T T G A A T C A G A A C T T A G T C T T G A A T C 亲代 子代