Which of the following descriptions are correct about the alternative splicing:()
A. The mechanism of alternative splicing is quite different from constitutive splicing.
B. Isoproteins can be produced from one gene.
C. Alternative splicing have different 5’ and 3’ splicing sites.
Different proteins can be produced in different tissues and different development stages.
E. It could be across exons, or involved in variable exons and retained introns
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SR protein:()
A. belongs to a protein family that have one or more arginine and serine-rich region
B. inhibit the identification and splicing of splicesome by binding to the splicing site of the intron
C. is a kind of activator of splicing.
D. is often binding to the splicing enhancer sequences of the intron.
Which of the following description is NOT correct about the behavior of post-transcriptional mRNA in eukaryotic cells?()
A. mRNA is combined with several proteins all the time after its transcription.
B. Mature mRNA is not combined with proteins, and is transferred across the nucleopore with its 5’ cap.
C. The splicing of pre-mRNA may be tissue-specific.
D. Isoproteins could be produced by RNA alternative splicing and RNA editing.
Which of the following description is NOT correct about the function of the 5’ cap of mRNA in eukaryotic cells?()
A. To protect mRNA and prevent it from degradation
B. To promote the translation of mRNA
C. To regulate the expression of mRNA from the promoter
D. To help mRNA to transfer out of the nuclear
Please give the correct order for the following steps of RNA capping process:①7’-methylation of guanosine.②Removal the last phosphate at 5’ terminal of pre-mRNA③The GMP cap is added to the pre-mRNA④The second nucleotide is methylated()
A. 1,2,3,4
B. 2,3,1,4
C. 1,4,3,2
D. 2,4,1,3
E. 4,3,2,1
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