In the genetic exchange experiment, why was the Hfr strain unable to obtain the genetic material...

In the genetic exchange experiment, why was the Hfr strain unable to obtain the genetic material it needed to survive on the plate?

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Q: In the genetic exchange experiment, why was the Hfr strain unable to obtain the genetic material it needed to survive on the plate

Hfr or the F⁺ cells are the donor cells whereas F^- cells are the recipient cells.
The gene transfer in E.coli cells is non-reciprocal, therefore, one of the strain acts as the donor strain and the other strain acts as the recipient strain (that receives the genetic material).
The donor strain contains transmissible fertility factor (F⁺) whereas the recipient strain is F^-.
F⁺ can also acts as a recipient strain but F^- cannot act as a donor strain. Hfr strains also called high frequency recombinants are capable of transmitting chromosomal genes in high frequency.
Conjugation event is represented as. Hfr (donor) x F^- (recipient)
F^- cells are without F plasmid and therefore, these cells can only act as recipient cells and they cannot donate the genetic material to Hfr cells. As a result of this, in the genetic exchange experiment, the Hfr strain was unable to obtain the genetic material it needed to survive on the plate.

gladiator answered 2 years ago

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