VECTORS IN CLONING, PLASMIDS

Q.        Define vector?

Ans:    It is a DNA molecule known to replicate autonomously in

a host cell to which a segment of DNA may be spliced to allow its replication, for example,.a plasmic or a temperate phage DNA.

Q. Give briefly essential features of vector?

Ans:    (i) It should be able to replicate within host cell.

(ii)     It must be capable of interaction into host cell.

(iii)     It must have a selectable marker.

(iv)      It must contain a site for interaction of target DNA.

Q.        What are plasmids? Also give their significance?

Ans:    Plasmids are extrachromosal circular pieces of DNA that

are found in bacteria. The first cloning vector was a plasmid. Plasmids remain key cloning vectors in recombinant DNA.