Which of the following mRNA molecules can form the most stable stem ring structure()
A. 5’....GGCUU.........UUCGG......3’
B. 5’....GGCUU.........AAGCC.......3’
C. 5’....GGCUU.........GGCUU......3’
D. 5’....GGCUU.........CCGAA.......3’
E. 5’....AAGCC.........AAGCC......3’
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Gene silencing mutations can lead to()
A. The nucleotide sequence of mRNA encoded by this gene did not change
B. The amino acid sequence of the protein encoded by the gene does not change
C. The protein encoded by this gene will not be expressed
D. An amino acid in the protein encoded by the gene will be replaced by another amino acid,but it will not change the function of the protein
E. Transposition of transcription reading frame
Which one of the following statements about the damage of UV to DNA of living cells is not true?()
A. Damage prevents normal DNA replicating
B. The most damaging wavelength is 260nm
C. To form a covalent bond between adjacent pyrimidines
D. The phosphodiester bond between adjacent nucleotides is broken
E. Most cells can synthesize proteins to repair UV damage
Among the operons with weak regulation, the mutation that causes the overexpression of the product gene is most likely to occur in()?
A. operatorgene
B. RNA 3 'terminal sequence
C. RNA 5 'terminal sequence
D. RNA intron
E. Coding genes of trans-acting element
What can be used when an oligonucleotide containing a damaged base is produced in a cell?()
A. Photoreactivation repair
B. Excision repair
C. Recombination repair
D. SOS repair
E. Mismatch repair
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