Question

How do bacteriophages and plasmids serve as tools of recombinant DNA technology?

Answer 1

Recombinant DNA technology:

1. Recombinant DNA technology is the process that involves the production of a modified gene in large amounts to introduce into a host organism for manipulating its genetic makeup.
2. The process involves plasmids which act as a vector tool to insert the gene of insert for developing the recombinant DNA molecule.
3. Bacteriophages are viral cells that attack bacteria and help in the multiplication of recombinant DNA.
4. Bacteriophages have two life cycle stages, in the lytic phase, they replicate and infect bacterial cells rapidly, whereas in the lysogenic phase the viral DNA is inserted and stays dormant for multiple replicative cycles as a prophage.
5. In the lytic phase, the phage genes are expressed to produce the viral proteins.
6. The proteins are packaged to produce new phage molecules.
7. The phage molecules are released by lysing the cell.
8. In the lysogenic cycle, the prophage stays dormant for many cycles of DNA replication.
9. The prophage is integrated into the host DNA and is passed to the daughter cell.
10. When UV light is emitted on such cells, the phage can enter into the lytic cycle from the lysogenic cycle to kill the host cell.

Bacteriophages replicate through the lytic phase cycle while the phage genome is inserted into the cell. The phage genes are expressed and the phage proteins and DNA are made.