試題詳解

58. Transcription generates pre-mRNA and undergoes modification with 5'cap and 3' poly-A tail. Which of the following statements about the structure and function of these pre-mRNA alterations is NOT correct?
(A) poly-A tails are usually consisting of 50-250 adenine
(B) facilitate the export of mature mRNA from the nucleus
(C) protect mRNA from hydrolytic degradation
(D) help ribosomes attach to 3' end of mRNA in cytosol
(E) none