The following points highlight the 3 modes of gene transfer and hereditary recombination in germs. The modes are: 1. Transformation 2. Transduction 3. Bacterial Conjugation.
Mode no. 1. Change:
Historically, the development of change in germs preceded one other two modes of gene transfer. The experiments carried out by Frederick Griffith in 1928 indicated for the very first time that a gene-controlled character, viz. Development of capsule in pneumococci, could possibly be used in a variety that is non-capsulated of germs. The transformation experiments with pneumococci ultimately resulted in a similarly significant finding that genes are constructed with DNA.
During these experiments, Griffith used two strains of pneumococci (Streptococcus pneumoniae): one having a polysaccharide capsule creating ‘smooth’ colonies (S-type) on agar dishes that was pathogenic. Læs videre Exactly about Gene Transfer and Genetic Recombination in Bacteria