(i) Name the organism in which the vector shown is inserted to get the copies of
the desired gene.
(ii) Mention the area labelled in the vector responsible for controlling the copy
number of the inserted gene.
(iii) Name and explain the role of a selectable marker in the vector shown.
(i) Escherichia Coli.
(iii) (a) The genes encoding resistance to antibiotics such as ampicillin (ampR), tetracycline
are used as selectable markers.
(b) Selectable markers helps in identifying and eliminating non-transformants and selectively
permitting the growth of the transformants.
(c) With the help of restriction enzyme cut BamH I i.e. the site ofpBR322, they ligate
a foreign DNA in the vector. The recombinant plasmids will lose tetracycline resistance
due to insertion of foreign DNA but can still be selected out from non-recombinants on
ampicillin containing medium. The transformants growing on ampicillin containing medium
are then transferred on a medium containg tetracycline. The recombinants will grow in
ampicillin containing medium but not in tetracycline medium. Non recombinants will grow on
medium containing both the antibiotics.