Question

In an experiment, E.coli cells have been genetically modified through site directed mutagenesis. This is a process through which specific locations in an organism’s genome can be altered in order to study the function of such locations, or proteins coded for by genes found in a location. There are many techniques available for site directed mutagenesis. (You have access to PCR ingredients, any primer you wish, laboratory equipment, Lambda phage, and the ability to alter Lambda genome, a commercially available plasmid, such as Puc19, E.coli K-12, plates, media, etc..)

3. What happens if you insert a piece of DNA into a cell by itself? (2 points)

Answer 1

If you try to insert a piece of foreign DNA by itself into host cell then host cell will not accept the DNA chunk since, they feel it does not belong to their cell or system and no transfer of desired DNA will be posssible,while if you use any vector, bacteriophage, plasmid depending upon your required gene of interest that need to be transferred.

Example, In case you use vectors, they have selectable marker,ORI region( PCC 19,PBR 322) .

While lambda phage has ability to attack bacterial cell insert the desired gene by breaking bacterial genome using holins and lysins, once bacterial genome or nucleus is destroyed large copies of desired DNA can be made using host cell or machinery.