Synthesis of $DNA$ takes place by

Which one of the following makes use of $RNA$ as a template to synthesize $DNA$?

Consider the process that a cell uses to replicate its double strand $DNA$ to make copies for daughter cells. Which statement describes the $DNA$ in daughter cells?

If $E. coli$ is grown in a $^{15}N$ medium for $80$ minutes,starting from a $^{14}N$ medium,what will be the ratio of light to hybrid $DNA$ molecules obtained?

Given below are two statements.
Statement $I$ - The template strand with free $3'$ end is called leading template and the strand with free $5'$ end is called lagging template.
Statement $II$ - Replication always starts at the $3'$ end of the template strand and proceeds towards the $5'$ end of the template.
In the light of the above statements,select the correct option given below:

$A$ discrete multiprotein structure on the chromosome which contains enzymes for $DNA$ duplication is called as