$A$ 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 $\%$)?

Briefly describe the scheme of $DNA$ replication proposed by Watson and Crick.

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:

Bacteria were grown in a medium containing a heavy isotope of nitrogen $(^{15}N)$ for many generations,and all their $DNA$ contained only heavy nitrogen. $A$ bacterium of this type was transferred to a normal medium and allowed to duplicate. After two divisions,the distribution of heavy $DNA$ is likely to be:

$A$ $N^{15}-N^{15}$ $\text{DNA}$ molecule is continuously replicated in $N^{14}$ medium,then what is the percentage of heavy $\text{DNA}$ in the $4^{\text{th}}$ generation (in $\%$)?

Which of the following diagrams correctly represents the process of $DNA$ replication at the replication fork?