Question

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

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

Answer 1

The correct option is A Escherichia coli and Agrobacterium tumefaciens

E. coli is used as recipient of rDNA because gene manipulation is technically easier in it than in any other organism. Thus, it is almost impossible to clone and manipulate DNA in any other organisms if the same cannot manipulate E. coli DNA. Therefore, DNA from the desired organism is first manipulated in E.coli and followed by its transfer to the host or another organism. Agrobacterium tumefaciens is a soil plant pathogenic bacterium that carries Ti plasmid. It can transfer a particular segment of the tumor-inducing (Ti) plasmid into the nucleus of infected cells. The transferred T-DNA is then integrated into the host genome and transcribed with it. This ability of Agrobacterium tumefaciens to transfer the T-DNA in host genome is explored in genetic engineering to transfer the desired DNA segment, carrying the gene of the interest, into genome of selected organisms. Correct answer is A.