Statement I: The tumour inducing plasmid (Ti plasmid) of Agrobacterium tumefaciens acts as a cloning vector in recombinant DNA technology.
Statement II: The Ti plasmid which is used in the mechanisms of delivering genes to a cell remains pathogenic.
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → Only Statement I is correct.
Agrobacterium tumefaciens is a pathogen of several dicot plants. Its tumour inducing (Ti) plasmid has been changed into a cloning vector that is no more pathogenic to plants but still uses the old delivery mechanism to put genes of our interest into plants.
Statement I: The tumour inducing plasmid (Ti plasmid) of Agrobacterium tumefaciens acts as a cloning vector in recombinant DNA technology. — True. The Ti plasmid has been modified into a cloning vector for delivering genes into a variety of plants.
Statement II: The Ti plasmid which is used in the mechanisms of delivering genes to a cell remains pathogenic. — False. The modified Ti plasmid is no longer pathogenic to plants. Only its ability to deliver genes has been kept.
NCERT Extract:
Cloning Vectors – “… A better understanding of the art of delivering genes by pathogens in their eukaryotic hosts has generated knowledge to transform these tools of pathogens into useful vectors for delivering genes of interest to humans. The tumor inducing (Ti) plasmid of Agrobacterium tumifaciens has now been modified into a cloning vector which is no more pathogenic to the plants but is still able to use the mechanisms to deliver genes of our interest into a variety of plants.”