Match the features that are required to facilitate cloning of alien DNA into a vector.

Choose the correct answer from the options given below:

 A-IV, B III, C-II, D-I

• The correct answer is Option (1) - A-IV, B III, C-II, D-I

• List I: Features to facilitate	List II: Cloning Vector
  A. Origin of replication (ori)	IV. sequence from where replication starts
  B. Selectable Marker	III. helps in identifying and eliminating non-transformants
  C. Cloning sites.	II. Recognition sites commonly used for restriction enzymes
  D. Vectors for cloning genes in plants	I. Agrobacrerium tumifaciens

   
• An origin of replication is a sequence of DNA at which replication is initiated on a chromosome, plasmid or virus. For small DNAs, including bacterial plasmids and small viruses, a single origin is sufficient.
• The selectable marker is a DNA sequence that aids in detecting and eliminating non-transformants while allowing transformants to grow selectively. For this purpose, the vector needs a selectable marker. A selectable marker is required for the plasmid's maintenance in the cell. The plasmid becomes helpful to the cell due to the presence of a selection marker. Under selective conditions, only cells harbouring plasmids containing the appropriate selectable marker will survive. In the cloning of vectors, genes that provide resistance to various antibiotics are commonly utilized as selection markers.
• The recognition sites on plasmids are known as cloning sites. These are the locations in the vector where recombinant DNA is cloned. It is the site where DNA is inserted into the vector. Restriction enzyme recognises the recognition site and cuts the DNA for insertion of foreign DNA. EcoRI and BamHI, are the examples.
• Ti plasmid is the most commonly used natural vector for cloning genes in plants. It is present in Agrobacterium tumifaciens and is used by the bacterium to cause a tumour in plants. The T-DNA region of the plasmid can be modified (genetically engineered) to disrupt (remove) a tumour-causing gene and introduce a foreign gene, which can then be introduced into the plant by infecting the plant with the plasmid.