$DNA$ is synthesized from viral $RNA$ using the enzyme:

For proving the semi-conservative mode of replication of $DNA$,$E. coli$ were first grown in a medium containing?

$DNA$ polymerases catalyse polymerisation in:

$A$ bacterium containing fully radioactive $DNA$ is allowed to replicate in a non-radioactive medium for two generations. What percentage of bacteria should contain radioactive $DNA$ (in $\%$)?

$A$ completely radioactive double-stranded $DNA$ molecule undergoes two rounds of replication in a non-radioactive medium. What will be the radioactive status of the four daughter molecules?

Discuss the significance of the heavy isotope of nitrogen in the Meselson and Stahl experiment.