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; its plasmids (e.g. pBR322) are used as cloning vectors.
⇒ Agrobacterium tumefaciens (a pathogen of dicot plants) delivers T-DNA through its Ti plasmid; 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)