Question

While cloning vectors, which of the two will be preferred by biotechnologists - bacteriophages or plasmids. Justify with reason.

Answer 1

While cloning plasmids are preferred by biotechnologist. Because there are some features to be an idol vector which includes; It must have low molecular wieght, have selectable marker, must contain multiple cloning sites, have high copy number and most importatly capable of replicating in host.

All these features are present in plasmids, But in case of bacteriophase it is large in size and it can only used for large size host, as it accomodates a maximum 24.6 kb foriegn DNA molecules for cloning.

Answer 2

Plasmids often contain genes encoding enzymes that confer a certain selective advantage to the host cell. Such selective advantages include resistance to certain antibiotics. In other cases, the conferred advantage can be the synthesis of antibiotics or various toxins. As the replication of plasmids is independent of the expression of cellular proteins (the required enzymes have long half-lives in the cell), the inhibition of protein synthesis in the host cell (achieved, for instance, by chloramphenicol) can be used for the inhibition of the replication of the chromosomal DNA, with the concurrent maintenance of the replication of plasmid DNA.