DNA Transfer by Conjugation Is More Efficient in a Liquid

question 42

Multiple Choice

DNA transfer by conjugation is more efficient in a liquid medium setting, subjected to very mild agitation (stirring) , rather than on an agar plate format. Why?

• A) Direct cell-to-cell contact is required for this process, and this is more likely to be achieved in the plate format than in the fluid format (especially for relatively non-motile types of bacteria).
• B) Direct cell-to-cell contact isn't required for this process, so the ability to secrete the DNA into the surrounding fluid medium makes the process more efficient than the dry surface of an agar plate.
• C) Direct cell-to-cell contact is required for this process, and this is more likely to be achieved in the fluid liquid format than on an agar plate (especially for relatively non-motile types of bacteria).
• D) Trick question-it can take place with the same degree of efficiency on either format. It doesn't matter!
• E) Agitation is only needed if the bacteria are known to be non-motile and can't move around on a solid medium. Otherwise, it doesn't really matter what type of medium is used as long as it contains chemicals to make cells competent.