Class 12th Biology 2014 Set3 Delhi Board Paper Solution
Question 20
How did the process of RNA interference help to control the nematode from infecting the roots of tobacco plants?
Answer
RNA Interference (RNAi) is a gene-silencing process that blocks the expression of genes in the parasite when it enters the host's body.
RNAi is a method adopted to prevent infestation of roots of tobacco plants by a nematode Meloidegyne incognitia. In RNAi, a complementary RNA binds to mRNA to form a ds RNA that cannot translate and hence, its expression is blocked (Silencing). In this process, nematode-specific genes (DNA) are introduced in the host plant. This introduced DNA forms both sense and anti-sense RNA. These two strands, being complementary to each other, bend and form ds RNA, leading to RNA interference. mRNA of nematode is thus silenced and the parasite cannot survive in the transgenic host.Thus, through the above method, tobacco plants can be protected from nematode attack.
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