Lambda phage which is true:
Ans. B. Lytic & lysogenic conversion cannot occur togethera. Lambda phage is dsDNA phage of E. coli discovered by Lederberg in 1950. It shows 2 types of cycles- lytic or temperate. In lysogenic cycle, it gets inserted only between the genes determining galactose utilization and biotin utilization due to the presence of site specific recombinase.b. On induction of the lytic cycle, the integration is reversed and the phage genome is excised at the same site as the integration.c. Occasionally, however, excision process occurs between two sites other than the normal attachment regions of the phage and host DNA, usually one within the prophage and one just outside. The consequence is that a ring of DNA is excised that contains primarily of lambda genes and a few host genes from either side of the attachment site. This hybrid DNA can be packaged in a lambda head and released, where it is able to infect a further cell and inject into it DNA that contains some host genes. This is an example of specialized transduction.
It causes mad cow disease
Lytic & lysogenic conversion cannot occur together
In Lysogenic phase host chromosome and remains dormant
Lytic phase incorporates in host DNA, proliferate & causes rupture of cell
Virology