A biologist wishes to take a useful gene found in penguins and introduce it into some bacterial cells. Her experimental procedure is given below.

Use a restriction enzyme to cut a gene out of the penguin DNA.
Use a restriction enzyme to cut open a plasmid.
Treat the plasmid with DNA ligase.
Treat the plasmid with DNA polymerase.
Introduce the plasmid into bacterial cells.

A step is missing. Where should it go in this procedure?

“Mix the desired gene and plasmid together” should go after step 5.
“Mix the desired gene and plasmid together” should go between steps 3 and 4.
“Mix the desired gene and plasmid together” should be the first step.
“Mix the desired gene and plasmid together” should go between steps 2 and 3.