Question

Which is used for the introduction of alien DNA into the animal cell?

• A. Agrobacterium tumefaciens
• B. Retroviruses
• C. Biolistics method
• D. Both b and c

Answer 1

The correct option is B Retroviruses

Retroviruses in animals have the ability to transform normal cells into cancerous cells. Retroviruses are disarmed and used to deliver desirable genes into animal cells. So, once a gene or a DNA fragment has been ligated into a suitable vector it is transferred into a bacterial, plant or animal host (where it multiplies).

Biolistics technique also known as ballistic method of DNA delivery has general applicability to plant species and can be used to virtually deliver DNA into all tissues. In this technique, the DNA-coated particles are propelled by a pressurised gun called the gene gun to introduce the alien DNA into the plant cells.

Agrobacterium tumifaciens is a pathogen of several dicot plants which is able to deliver a piece of DNA known as ‘T-DNA’ to transform normal plant cells into a tumor and direct these tumor cells to produce the chemicals required by the pathogen.