沒有 【段考】高二生物下學期 權限，請先開通．

沒有 【段考】高二生物下學期 權限，請先開通．

沒有 【段考】高二生物下學期 權限，請先開通．

沒有 【段考】高二生物下學期 權限，請先開通．

沒有 【段考】高二生物下學期 權限，請先開通．

沒有 【段考】高二生物下學期 權限，請先開通．

1. In higher eukaryotes, which statement about a transcription activator is not true? (A) It might direct DNA methylation. (B) It might interact with chromatin-remodeling factors. (C) It might lead to H3 lysine 4 methylation. (D) It might direct histone acetylation. (E) The mediator complex forms a molecular bridge between the activator and RNA Pol II.

2. What description about micro RNAs (miRNAs) is incorrect? (A) Most miRNAs are transcribed by RNA Pol II. (B) One type of miRNAs can target to many mRNAs. (C) The mature miRNAs are about 21-22 nucleotide, which hybridize perfectly with their target mRNAs.(D)They associate with Ago protein to form RISC (RNA-induced silencing complex) complex. (E) They can induce mRNA degradation or inhibit mRNA translation.

3. The exons of nuclear pre-mRNA have to be removed for mature mRNA synthesis. Which is incorrect? (A) One transesterification reaction results in splicing of exons in pro-mRNA. (B) The spliceosome is a snRNAs complex to catalyze the exon removals without ATP. (C) The splicing is preformed after thtranscription termination. (D) Only 1% of human genes undergo alternative splicing to yield different mRNAs that encode distinct proteins. (E) SR proteins contribute to exon definition.

4.Which part of the ribosome is responsible for peptidy1 transfer? (A) LSU (B) SSU (C)mRNA (D)tRNA (E) SiRNA

5.Transporting macromolecules to the nucleus through nuclear pores from the cytosol typically requires which one's help? (A) Epinephrine (B) Exportin (C) Importin (D) AMPK (E) mTOR