Who constituted the first rDNA? Name the vector and host used for the process.

Hint: Recombinant DNA is technology where a piece of DNA which is created by combining DNA fragments from two different sources. It is possible because the molecular structure of DNA all organisms have the same chemical structure, and differ only in the sequence of nucleotides in the whole identical structure.

Complete answer:
The technology to propagate and express recombinant genes was developed by Stanley Cohen and Herbert Boyer in 1973. It made it possible to convert bacterial cells into living factories for the selected proteins to be produced directly. In the Salmonella typhimurium bacterium, they cut a piece of DNA from a plasmid carrying the antibiotic resistance gene and related it to the Escherichia coli plasmid.
The creation of recombinant DNA requires a cloning vector, a DNA molecule that replicates within a living cell. Vectors are typically derived from plasmids or viruses and represent relatively small segments of DNA containing the genetic signals necessary for replication, as well as additional components for ease when injecting foreign DNA, recognize cells containing recombinant DNA and where appropriate, express foreign DNA. The choice of a molecular cloning vector depends on the choice of the host organism, the size of the DNA to be cloned, and whether it is foreign DNA.to be expressed and how. The DNA segments can cut and ligate by using a number of techniques, such as restriction enzyme and DNA ligase respectively.

Note: Recombinant DNA technology is an important tool in vaccine production, insulin, interferon, and human growth hormone. It is also used in production of clotting factors that are used for treatment of haemophilia and also in gene therapy.