This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Biochemistry
Nobel prize in 2006 (recently) was given for the discovery of 
Select and explain. 
A. Lipoxins, B. RNAi, C. mt DNA, D. β-transcription factor
B: RNAi
Answer: B: RNAi 
Explanation: If an investigator introduces into an organism a duplex RNA molecule corresponding in sequence to virtually any mRNA, Dicer nuclease cleaves the duplex into short segments, called small interfering RNAs (siRNAs). These short (21-25 nucleotide long) si RNAs usually form perfect RNA-RNA hybrid with their targets potentially anywhere within the length of mRNA where the complementary sequence exists. Formation of such RNA-RNA duplexes between si RNAs and mRNA results in reduced specific protein production because the si RNA - mRNA complexes are degraded, mostly in specific cytoplasmic organelles termed P-bodies. The process is known as RNA interference (RNAi) for which Nobel prize was given to Andrew Fire & Craig Mello in 2006.