Question

Two microbes found to be very useful in genetic engineering are-

• A. Crown gall bacterium and Caenorhabditis elegans
• B. Escherichia coli and Agrobacterium tumefaciens
• C. Vibrio cholerae and a tailed bacteriophage
• D. Diplococcus sp and Pseudomonas sp

Answer 1

Answer: (B)

Escherichia coli and Agrobacterium tumefaciens

Answer 2

E.coli contains many important standard cloning vectors widely used in gene cloning experiments like PBR322 contains origin of replication (ori). Other cloning vectors like PACYC177, PBR324, PRK 64.6 contain ampicillin resistance gene they are also found in E.coli. Among higher plants, Ti plasmid of Agrobacterium tumefaciens and Ri plasmid of A. rhizogenes is the best known vector.
T-DNA from Ti or Ri plasmid of Agcobacterium is considered to be a very potential vector for cloning experiments with higher plants.