The accurate response is "Hfr strains integrate the F plasmid into their chromosome".
This relates to the process of horizontal gene transfer in bacteria, which involves the movement of an "F plasmid" during bacterial conjugation. Bacteria possessing the F plasmid are called "F+ strains". The primary distinction between Hfr strains and F+ strains lies in that the former has the F plasmid integrated into their chromosome, whereas the latter retains the F plasmid freely in the cytoplasm without integration into their genetic material.
Work is defined as being completed when an object shifts as a result of an applied force. It is calculated by multiplying the force exerted by the distance moved as a result of that force. It can be represented as: W = Force x distance
W = 84 J = F (7.0 m)
F = 12 N
I hope this provides clarity.
