GATE2016-36

Question

A $1.2$ kb DNA fragment was cloned into $\textit{Bam}$HI and $\textit{Eco}$RI sites located on a $2.8$ kb cloning vector. The $\textit{Bam}$HI and $\textit{Eco}$RI sites are adjacent to each other on the vector backbone. The vector contains an $\textit{XhoI}$ site located $300$ bp upstream of the $\textit{Bam}$HI site. An internal $\textit{XhoI}$ site is present in the gene sequence as shown in the figure. The resultant recombinant plasmid is digested with $\textit{Eco}$RI and $\textit{Xhol}$ and analyzed through $1 \%$ agarose gel electrophoresis. Assuming complete digestion with $\textit{Eco}$RI and $\textit{Xhol}$, the DNA fragments (in base pairs) visible on the agarose gel will correspond to:

• A. $2800$, $700$ and $500$
• B. $2800$, $700$ and $800$
• C. $2500$, $700$ and $800$
• D. $2500$, $1200$ and $300$