Consider the following statements and choose the correct answer:<br>In order to be a useful vector, a plasmid:<br>1. Must possess the genes essential for replication of DNA<br>2. Must carry, at least, one gene that can be used as a marker for the selection of the plasmid in the transformed cell<br>3. Must include, at least, one gene recognizable by its product or activity, which possesses within it a cutting site for a restriction enzyme<br>4. In the rep region must contain a cutting site for the restriction enzyme to be used

Correct Answer: Only 1, 2 and 3 are true