Gene Delivery Vectors from Pathogens — NEET Biology
✅ Asked in NEET 2024Vectors for cloning genes in plants and animals: You may be surprised to know that we have learnt the lesson of transferring genes into plants and animals from bacteria and viruses which have known this for ages – how to deliver genes to transform eukaryotic cells and force them to do what the bacteria or viruses want. For example, Agrobacterium tumifaciens, a pathogen of several dicot plants 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. Similarly, retroviruses in animals have the ability to transform normal cells into cancerous cells. A better understanding of the art of delivering genes by pathogens in their eukaryotic hosts has generated knowledge to transform these tools of pathogens into useful vectors for delivering genes of interest to humans. The tumor inducing (Ti) plasmid of Agrobacterium tumifaciens has now been modified into a cloning vector which is no more pathogenic to the plants but is still able to use the mechanisms to deliver genes of our interest into a variety of plants. Similarly, retroviruses have also been disarmed and are now 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).
NTA tests whether students understand how Agrobacterium tumefaciens and retroviruses naturally deliver genes into eukaryotic cells, and how these pathogenic mechanisms have been repurposed as cloning vectors. The T-DNA from Agrobacterium is integrated into plant cells to cause tumors—this same process is now modified to deliver useful genes without causing disease. Students often confuse the original pathogenic function (causing tumors) with the engineered vector function (delivering desired genes safely). Remember: pathogens are 'disarmed' or modified to remove pathogenicity while retaining their gene-delivery ability. This concept appeared in 2023 and 2024 NEET exams because it bridges microbiology and biotechnology applications, testing conceptual understanding rather than mere recall.
This paragraph was tested 2 times in NEET.
The "Ti plasmid" of Agrobacterium tumefaciens stands for (NEET 2024)
Which of the following statement is incorrect about Agrobacterium tumefaciens? (NEET 2023)
Through deep analysis of NEET and NTA, 88 of 90 questions from the NEET 2026 paper were matched straight from the MedicNEET Biology question bank.
88/90MedicNEET's Biology question bank is built from the same NCERT lines NTA picks repeatedly. Not random MCQs — questions crafted exactly like NTA crafts them.