Which causes uncontrolled growth of plant tissue, resulting in a tumor? A. RhizobiumB. AgrobacteriumC. Bacillus anthracisD. Yersinia pestis

Answer: Agrobacterium

Explanation:

Agrobacterium tumafaciens is the causal agent of tumors in flowering plants.

It is a soil bacterium which enters the plant through wounds in roots or stems. When this happens, the bacterium inserts a segment of DNA called "T-DNA," from a plasmid, into the plant cell. This is incorporated at a semi-random location into the plant genome. Then this stimulates the plant tissues to grow in a disorganised way, producing swollen galls.