Gel electrophoresis is used for

Can you think and answer how a reporter enzyme can be used to monitor transformation of host cells by foreign $DNA$ in addition to a selectable marker?

Which of the following methods is used for the isolation of $DNA$?

Polymerase chain reaction $\text{(PCR)}$ amplifies $\text{DNA}$ following the equation:

Which technique is used to check the progression of a restriction enzyme digestion?

Given below are two statements:
Statement $I:$ The $\text{DNA}$ fragments extracted from gel electrophoresis can be used in the construction of recombinant $\text{DNA}$.
Statement $II:$ Smaller size $\text{DNA}$ fragments are observed near the anode while larger fragments are found near the wells in an agarose gel.
In the light of the above statements,choose the most appropriate answer from the options given below: