Question

1. How   can   lysis   occur   if   a   lambda   phage   has   already   formed   a   stable   lysogeny?  

2. In   generalized   transduction,   only   1   or   2   progeny   phage   may   function   as   transducing   particles.   On   the   other   hand,   in   specialized   transduction,   all   the   progeny   phage   are   transducing   particles.   With   the   aid   of   a   diagram,   explain   this   statement.      

3. Is   the   bacteriophage   carrying   donor   bacterial   DNA   (transducing   particle)   capable   of   producing   progeny   phage?   

Answer 1

1. How   can   lysis   occur   if   a   lambda   phage   has   already   formed   a   stable   lysogeny?  

Tha fate of bacteriophage repliaction is determined by the two phage proteins called Int and CI. The stability of CI determines the phage lifecycle. When the protein CII is degraded the phage will undergo lytic phase from lysogenic phase. When there is a DNA damage or inhibition of replication in the host, the stable lysogenic can also undergo epigenetic switch to the lytic pathway induced by the activation of host RecA protein triggered cleavage of CI.

2. In   generalized   transduction,   only   1   or   2   progeny   phage   may   function   as   transducing   particles.   On   the   other   hand,   in   specialized   transduction,   all   the   progeny   phage   are   transducing   particles.   With   the   aid   of   a   diagram,   explain   this   statement.      

3. Is   the   bacteriophage   carrying   donor   bacterial   DNA   (transducing   particle)   capable   of   producing   progeny   phage?

No. The bacteriophages produced by generalized and lateral transduction those carring transducing particles that contains only the bacterial DNA are not capable of producing progeny phage because they lack the phage genes.