Question

Discuss how bacteriophages cause mutations

(in a long paragraph essay )

Answer 1

1. Bacteriophange is the virus that infects bacteria. It is first observed by Twort and d'hrrelle in 1915 and 1917. They are obligate parasite that multiply inside bacteria by making use of some or all of the most biosynthetic machinery.
2. But it acts as model for animal cell viruses.
3. gene transfer in bacteria.

• Bacteriophage causes induced mutation in E.coli Bacteria contain special genetic material called episomes. Some episomic elements are- Sex factor of E.coli strain K12 etc. The temperate bacteriophage Mu1 causes severe genetic modification in its genetic modification in its natural host E.coli K12. The prophage of Mu1 abolishes normal phenotypic expression of many host gene located at chromosomal sites of phage integration. this is called phage induced mutation. It is explain as the lysogenization is a essential step for induced mutation. mutation may results from a physical association between host genes and prophage of Mu1. A non-lysogenic Hfr strain of e.coli was crossed to 6 lysogenic F negative recepients that carry single- phaged induced mutation at 6 different loci and severakl UV induced auxotrophy markers.