Question

The bacterium which produces crown gall disease in cotton

• A. Agrobacterium tumefaciens
• B. Escherichia coli
• C. Bacillus thuringiensis
• D. Streptomyces hygroscopicus

Answer 1

The correct option is A Agrobacterium tumefaciens

• Agrobacterium tumefaciens is a Gram-negative bacterium. It is the causative agent of crown gall disease in cotton.
• It has a Ti-plasmid which have the tumor causing genes. This gene causes formation of tumor when the plant is infected with the bacterium.
• The bacterium enters the plant when there is some wound or injury caused to the plant.
• Thus, the correct answer is option A.