Differentiate between Hfr and F–

Hfr (high frequency of recombination) and F- (fertility) are two types of bacterial cells that differ in their ability to transfer genetic material to other bacteria through a process called conjugation.

Hfr cells are able to transfer a portion of their genome to other bacteria at a high frequency, or more often than F- cells. This is because Hfr cells contain a special type of plasmid called an F plasmid, which has a region called the Hfr transfer origin that allows it to be transferred to another bacterium during conjugation.

F- cells, on the other hand, are unable to transfer their genome to other bacteria through conjugation. This is because they lack the F plasmid and do not have the Hfr transfer origin. F- cells are also called “non-fertile” cells because they are unable to transfer their genetic material to other bacteria and therefore cannot contribute to the production of offspring.