UPSC Civil Services 2013 Prelims General Studies Paper I

Recombinant DNA technology is the hybridization of DNA from different sources to achieve desired genotype and phenotype in an organism. The major tools required for rDNA technology are restriction enzymes, cloning vector and competent host.
Restriction enzymes are biological scissors that recognise and cut DNA at specific points. Eukaryotes do not have restriction enzymes. Vectors are cloning vehicles required to tansfer DNA of interest from one organism to another, e.g., bacterial plasmid, bacteriophage, cosmids, YAC and BAC. Competent host is the organism in which desired DNA is introduced with the help of vector. Host should have a specific DNA sequence called origin of repletion (Oric) which responsible for initiating replication E.g. Yeast, E. coli, plant and animal cells.