Which of the following is incorrect way to introduce alien DNA into host cells ? 

(i)Bacteria is made ‘competent’ to take up DNA by treating them with a specific concentration of a divalent cation, such as calcium.
(ii) Recombinant DNA is transfer into competent bacteria by incubating the cells with recombinant DNA on ice, heat shock, and then putting them back on ice.
(iii) Recombinant DNA is directly injected into the nucleus of plant cell by micro-injection.
(iv) Recombinant DNA is directly injected into the nucleus of an animal cell by biolistics or gene gun.
(v) ‘Disarmed Pathogen’ vectors, when allowed to infect the cell, transfer the recombinant DNA into the host.