When various strains of λ phage are seeded on a lawn of E. coli, they can form clear or turbid plaques.       (b) For mutant λ phages that can only form clear plaques, give two different types of mutation in the phage that can explain the clear plaque phenotype.

In 1965, Jon Beckwith and Ethan Signer devised a method of obtaining specialized transducing phages carrying the lac region. They knew that the integration site, designated att80, for the temperate phage φ80 (a relative of phage λ) was located near tonB, a gene that confers resistance to the virulent phage T1: tonB att80 They used an F ′ lac+ plasmid that could not replicate at high temperatures in a strain carrying a deletion of the lac genes. By forcing the cell to remain lac+ at high temperatures, the researchers could select strains in which the plasmid had integrated into the chromosome, thereby allowing the F ′ lac to be maintained at high temperatures. By combining this selection with a simultaneous selection for resistance to T1 phage infection, they found that the only survivors were cells in which the F ′ lac had integrated into the tonB locus, as shown here: tonB F lac att80 This result placed the lac region near the integration site for phage φ80. Describe the subsequent…

Lambda phage çan facilitate bacterial chemosomal DNA transfer through the process of specialized transduction / generalized transduction (copy and paste the correct answer) A by transferring specific bacterial DNA / bacterial DNA at random (copy and paste the correct answer) A from a donor cell / recipient cell (copy and paste the correct answer) A to a donor cell / recipient cell (copy and paste the correct answer).

You are designing a phage therapy for a cystic fibrosis patient with an multi-antibiotic resistant Mycobacterium infection. The Mycobacterium infection is preventing the patient from taking immunosuppressant drugs that are needed for a successful lung transplant. The idea is that introducing the right phage to the patient will kill the Mycobacterium cells and allow the patient to go on immunosuppressant drugs that will ensure the new lung is not rejected by the body.  You need to find a phage that infects the Mycobacterium you isolated from the patient. Which TWO options have the highest chance of success? A. Screening a colleague's library of known Mycobacterium phages for phage that infect the patient's Mycobacterium isolate   b. Choosing likely candidates from analysis of phage 16S rRNA phylogeny in the tree of life   C. Isolating new phage from soil using a plaque assay with the Mycobacterium isolate   D. Obtaining a very well-studied phage, such as T4 bacteriophage, that…