Question

1) You obtain the sequence of a gene containing 10 exons, 9 introns, and a 3′ UTR containing a polyadenylation consensus sequence. The fifth intron also contains a polyadenylation site. To test whether both polyadenylation sites are used, you isolate mRNA and find a longer transcript from muscle tissue and a shorter transcript from all other tissues. Briefly speculate about the mechanism involved in the production of these different transcripts.

2) Briefly speculate about why plants deficient in Dicer activity show increased sensitivity to infection by RNA viruses.

Answer 1

Answer:

Q-2):

• RNA silencing in multicellular plants and animals is mediated by ~21–24 nt small RNAs (sRNAs) that guide sequence-specific gene regulation, chromatin modification, and defense against viruses.
• These sRNAs are broadly classified into microRNAs (miRNAs) and small interfering RNAs (siRNAs), which have similar chemical structures but differ in function and mode of biogenesis.
• Production of both types of sRNAs depends on the activity of dicer proteins.
• Plants such as Arabidopsis have evolved a diversity of RNA silencing pathways, sRNA classes and DICER-LIKE (DCL) genes that is unmatched in other eukaryotes.

Please Rate My Answer..........Thank..........u...