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 # 1. Change:
Historically, the breakthrough of transformation in germs preceded one other two modes of gene transfer. The experiments carried out by Frederick Griffith in 1928 suggested when it comes to time that is first a gene-controlled character, viz. Development of capsule in pneumococci, could possibly be utilized in a non-capsulated selection of these germs. The transformation experiments with pneumococci ultimately resulted in a discovery that is equally significant genes are constructed with DNA.
In these experiments, Griffith utilized two strains of pneumococci (Streptococcus pneumoniae): one with a polysaccharide capsule creating ‘smooth’ colonies (S-type) on agar dishes that was pathogenic.