(a) Name the nematode that infects and damages tobacco roots.
(b) How are transgenic tobacco plants producced to solve this problem ?

Explanation

(a) Namatode Meloidegyne incognitia infects the roots of tobacca plant.
(b) (i) To prevent the roots of tobacco plants from infections a strategy was adopted based on the process of RNA interference (RNA)
(ii) Nematode-specific gene were introduced into the host plants using Agrobacterium vectors.
(iii) These two RNAs being complementary to each other formed a double stranded RNA (dsRNA) that initiated RNAi and thus, silenced the speciric mRNA of the nematode.
(v) The parasite could not survive in a transgenic host expressing specific interfering RNA thus, plant got itself protected from the parasite.