Sexuality and recombination in bacteria will involve transfer of genetic material from one bacterial cell to another. Following three methods for such a transfer are known and are illustrated in Figure 12.1. (i) Transformation. In this case, genetic material is released from one strain and a part may be acquired by another strain, which' thus gets transformed without coming in contact with the other strain (Fig. 12.IA). (ii) Transduction.
In this phenomenon, a virus when released from a host bacterial strain may carry with it a part of genetic material of the host strain and may transfer it to another strain later infected by this virus (Fig. 12.IB). (iii) Conjugation.
In this case, genetic material is transferred through a conjugation tube, when two strains come in contact (Fig. 12.1C).
A more detailed discussion on transformation is presented in Chemistry of the Gene 1. Nucleic Acids and Their Structure
; in this section only conjugation and transduction will be discussed in some detail. A brief discussion on linkage of genes revealed by transformation will also be included later in this section.