Kingdom Monera Reproduction - Transformation & Transduction
Description:
Transformation and transduction are processes by which DNA segments are transferred from one bacterium to another.
Transformation
Transformation is the process of absorption of DNA segment from the surrounding medium by a living bacterium.
This phenomenon was discovered by Griffith in 1928.
Receptivity for transformation is present for a brief period when the cells have reached the end period of active growth.
At this time, they develop specific receptor sites in the wall.
Normally E.coli do not pick up DNA but they can do so in the presence of calcium chloride.
Transduction
Transduction is the process of transfer of foreign gene by means of viruses.
Transduction was discovered by Zinder and his teacher Lederberg in 1952.
A virus may pick up pick up gene of host in place of its own gene during multiplication in the host cell. Such a virus is non virulent.
Virus passes over the gene of the previous host to the new host.