Explain the role of Ti plasmids in biotechnology.
Answer. Agrobacterium tumefaciens is a soil-inhabiting bacterium that may invade growing plants at the junction of root and stem, where it can cause a cancerous growth known as a crown gall. A. tumefaciens contains Ti plasmid which carries gene for tumour formation for using Agrobacterium tumefaciens as a cloning vector researchers deleted the genes which governs auxin and cytokinin production (the oncogene) from T-DNA of Ti plasmid, it is known as disarming. After disarming, this T-DNA is inserted into chromosomes of the host plant where it produces copies of itself.