Question

A plasmid occurs in the soil bacterium "Agrobacterium tumefaciens" infects all broad level agricultural crops such as tomato, soyabean, sunflower and cotton. It induces the formation of cancerous growth called a "crown gall tumour". This plasmid is:

• A. F-plasmid
• B. Ti-plasmid
• C. R-Plasmid
• D. Col–plasmid

Answer 1

The correct option is B Ti-plasmid

Crown gall, plant disease, caused by the bacterium Agrobacterium tumefaciens. Agrobacterium tumefaciens cell contains a plasmid known as the Ti (tumour-inducing) plasmid. A. tumefaciens infects the plant through its Ti plasmid. The Ti plasmid integrates a segment of its DNA, known as T-DNA, into the chromosomal DNA of its host plant cells which causes crown gall.