Question

Explain various modes of genetic recombination in bacteria.

Answer 1

Bacteria exchange genetic material by three main modes of recombination: transformation, transduction and conjugation.

1. Transformation: A recipient bacterium takes up free DNA released from a donor cell. The donor DNA may become incorporated into the recipient’s DNA, changing its genetic and phenotypic traits.
2. Transduction: A bacteriophage carries a fragment of DNA from one bacterium (donor) to another (recipient). The transferred DNA can recombine with the recipient’s chromosome.
3. Conjugation: DNA passes directly from a donor bacterium to a recipient through cell-to-cell contact, commonly involving a sex pilus and the F (fertility) factor. In some crosses, an Hfr donor can transfer a large portion of its chromosome, which may recombine with the recipient DNA.

These processes introduce new genetic combinations in bacteria without gamete formation or sexual reproduction as in eukaryotes.