chap- Biotechnology and its application

pg 210 ncert book fig 12.2 based on this fig. some ques r there plz ans it

i) Name the novel strategy, which is being explained in the above diagram?

ii) Name the parasite and its host for which it is adapted.

iii) Explain the steps of this novel mechanism

1. RNA interferance

2. Parasite is Meloidegyne incognitia and host is tobacco plant.

3.  RNA Interference (RNAi)

• 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, which cannot translate and hence, its expression  is blocked (Silencing).

Steps

• Nematode specific genes (DNA) were introduced in the host plant.
• The introduced DNA forms both sense and anti-sense RNA.
• Two strands being complementary to each other bend and form ds RNA, leading to RNAi.
• mRNA of nematode is silenced and the parasite cannot survive in the transgenic host.