Is there a difference between an F' plasmid that has taken up a
chromosomal gene that conveys antibiotic resistance, and an R
plasmid? Is a bacterium containing an R plasmid and yet lacking
an F+ plasmid capable of horizontal gene transfer by
conjugation? If I understand the nomenclature correctly, an R
plasmid is just any plasmid containing an antibiotic
(R)esistance gene (eg. Amp, Kan, Cm, etc.). It's a bit of an
outdated name from when people didn't know how exactly the
plasmids conferred such resistance. An F-plasmid is any plasmid
that contains the genes necessary for (F)ertility, eg:horizontal
gene transfer via the tra operon. The two do not have to appear
together -- eg: Many F plamids will contain resistance genes
(along with other random chunks from the genome), but resistance
doesn't always have to be part of the payload. Likewise, it is
common in labs to build pure resistance vectors that lack any
horizontal transfer capability in order to select for particular
clones.