Question
Biology Question on the molecular basis of inheritance
DNA replication is semi-conservative because ......
Only one of the parent strands acts as template
Both the strands of the new molecule are synthesised de novo
One of the strands in each molecule synthesised is parental and the other new
The daughter strands synthesised are dispersive
One of the strands in each molecule synthesised is parental and the other new
Solution
Semi conservative replication of DNA was proved by work of Meselson and Stahl (1958). They grew E.coli for many generations in medium with N till the bacterial DNA became completely labelled with N. Then they transferred it to N containing medium and first generation showed DNA with both N and N in equal amount. It proved semi conservative nature of replication i.e., the two resulting double strands are identical, and each of them consists of one original and one newly synthesized strand.