Question

Explain how rDNA gets introduced into a plant cell.

Answer 1

Hint: rDNA is the recombinant DNA molecules formed by the genetic recombination to get the genetic material from the multiple sources. The recombinant DNA is the common name for a piece of DNA that has been produced by combining two fragments from the two different sources.

Complete answer:
The DNA sequence which is used in the production of recombinant DNA molecules obtained from any species such as plant DNA is joined to bacterial DNA. The sequence of DNA is not found in nature but it is created by the chemical synthesis of DNA and integrated into the recombinant molecules. The recombinant DNA is produced in the laboratory by the process called molecular cloning. It is the most generally used method after the polymerase chain reaction. The formation of the recombinant DNA needs a cloning vector which is a DNA molecule that replicates within the living cell. The recombinant DNA is most commonly used in biotechnology, genetic engineering, medical and research fields.
There are several methods which are used in the introduction of recombinant DNA in different cells. Electroporation is a process in which the recombinant DNA is introduced in the plant cell. As the DNA molecules are hydrophilic and due to which it cannot pass through the cell membrane. So to increase their efficiency the bacteria is treated with a concentration of calcium which increases the efficiency of the DNA entering the bacterium through pores in its cell walls. The other method which is mainly suitable for plants is a gene-gun. In this process, the cell is bombarded with DNA with a high velocity of particles like gold coated with DNA molecules.

Note: The recombinant DNA is different from genetic recombination in such a way that the recombinant DNA is produced by the artificial method while the genetic recombinant is a biological process. The proteins that are produced by the recombinant DNA within a living cell are known as recombinant proteins.