Question

What statement about conjugation is true? Group of answer choices

A. Hfr strains are more useful for genetic mapping than F+ strains because Hfr strains can conjugate with any strain, while F+ strains can only conjugate with F- strains.

B. Hfr strains are more useful for genetic mapping than F+ strains because they recombine transferred genetic material in the recipient cell at a higher rate.

C. Hfr strains are more useful for genetic mapping than F+ strains because Hfr strains have an F plasmid integrated into the bacterial genome, and therefore can transfer bacterial genes near the integrations site.

D. Hfr strains are more useful for genetic mapping than F+ strains because F+ strains never carry bacterial genes.

Answer 1

Ans ) Statements-B,C and D are true regarding conjugation.

Explanation:

F+ strains are those which carry F plasmid in the cytoplasm.

Hfr and F+ strains usually conjugate with F- strains. So, statement A is wrong.

Hfr strains are the ones in which F plasmid is integrated into the host genome. These are also called high frequency of recombination strains and these cells show high frequency of recombination.So, statement B is correct.

Hfr strains are integrated into the host genome and sometimes while excising from the genome it carry some of the bacterial genes (near the integration site) along with it, resulting in transfer of these genes to the recipient.So, statement C is correct.

F+ strains carry free F plasmid in the cytoplasm and so after conjugation only F plasmid would be transferred and no other bacterial genes would be transferred.So, statement D is also correct.