Two microbes found to be very useful in genetic engineering are-
- Diplococcus sp. and Pseudomonas sp.
- Vibrio cholerae and a tailed bacteriophage
- Crown gall bacterium and Caenorhabditis elegans
- Escherichia coli and Agrobacterium tumefaciens
Answer
(4) Escherichia coli and Agrobacterium tumefaciens
Solution
As per NCERT, Escherichia coli is the most commonly used host, and its plasmids (e.g. pBR322) are used as cloning vectors.
Agrobacterium tumefaciens (a pathogen of dicot plants) delivers T-DNA through its Ti plasmid, so the disarmed Ti plasmid is used as a vector to transfer genes into plants.
∴ E. coli and A. tumefaciens are the two microbes very useful in genetic engineering.
Answer: (4)