DNA and Biotechnology Practice Test

Making cells competent means enabling them to take up DNA from their surroundings. In transformation, competent cells acquire naked plasmid DNA so that the genetic material can enter the cell and potentially be maintained and expressed. Lab methods—like chemical treatment or electrical pulses—open up the cell envelope just long enough for plasmid DNA to get inside, after which the plasmid can replicate if the origin of replication is compatible. This uptake step is the essential purpose of competence.

If DNA never gets inside, any desired genetic change won’t happen, so degradation of DNA or preventing plasmid replication wouldn’t accomplish the goal. Editing the genome via recombination requires the DNA to be inside the cell first, and transformation is the route that provides that inner DNA message. Some organisms are naturally competent and can take up DNA from their environment, but in lab settings we purposefully induce competence to enable plasmid uptake during transformation.