15. Which of the following three codons translate as serine (Ser)?
A.AGU
B.CGA
C.CAU
D.AUG

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16. The role of molecular chaperones is to
A.facilitate binding of ribosomes to mRNA
B.degrade newly synthesized polypeptides that contain inaccurate sequences
C.facilitate binding of RNA polymerase to DNA
D.aid a newly synthesized polypeptide in folding to its proper shape

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17. What is the action of tetracycline in prokaryotes?
A.It blocks translocation reaction on ribosomes
B.It blocks peptidyl transferase reaction on ribosomes
C.It blocks the binding of amino-acyl tRNA to the A site of ribosomes
D.Not known with certainity

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18. A quorum sensing system
A.detects a signal from the external environment
B.senses a compound produced by the bacterium itself
C.consists of a sensor component that phosphorylates a regulatory protein
D.controls the activity of ribosomes directly

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19. The Shine-Dalgarno sequence is
A.trailer sequence
B.a stop codon
C.the reading frame of a gene
D.a short sequence that acts as a ribosomal binding site

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20. Which of the following statement is correct?
A.The size and sequence of introns can be deduced from the cDNA sequence
B.Restriction endonuclease can cleave ss and dsDNA both
C.Restriction fragment length polymorphism (RFLP) is usually formed in coding sequence of a gene
D.Amino acid sequence of a protein can be deduced from corresponding cDNA nucleotide

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21. What was the first bacterial genome to be sequenced and made public?
A.Bacillus subtilis
B.Escherichia coli
C.Haemophilus influenzae
D.No bacterial genome has been sequenced yet

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