27. Pre-miRNA can be digested to mature miRNA by?
(A) Argonaute
(B) Slicer
(C) DGCR8/ Pasha
(D) Dicer

23. In the structure of mature tRNA, the three bases in the most 3' end are: (A) 5'-AAC-3' (B) 5'-CCA-3' (C) 5'-ACC-3' (D) 5'-CAA-3'

24. In precursor mRNA splicing, U6 snRNA can pair with two snRNAs and the intron site. These two snRNAs and intron site are: (A) U1 and U2, 5' splicing site (B) U1 and U4, 3' splicing site (C) U2 and U4, 5' splicing site (D) U2 and U5, 3' splicing site

25. In the infection of E. coli by λ phage, which description for the binding ability of cI is correct? (A)(B) (C)(D)

26. The ribosome-binding site in mRNA is named as? (A) Shine-Dalgarno sequence (B) Okazaki sequence (C) Kozak sequence (D) Watson and Crick sequence

28. The antibiotic puromycin can terminate translation by mimicking the structure of? (A) 16S rRNA (B) 23S rRNA (C) tyrosyl-tRNA (D) stem and loop structure of 3' UTR of mRNA

29. Which enzyme is NOT involved in RNA editing? (A) RNA ligase (B) terminal uridylyl transferase (TUTase) (C) RNA triphosphatase (D) exo-nuclease

30. The protein-protein interaction can be detected by: (A) Far western blot (B) Western blot (C) Northern blot (D) Southern blot

1. Chi sites are _________. (A) generated from Holliday junctions (B) inverted repeats (C) binding sites for RecA protein (D) specific sequences in prokaryotic genomes where crossovers occur (E) specialized single-stranded region

2. A single nucleotide deletion occurred in a gene. The change is indicated below. What is the consequence of the mutation? ......AGT CGA TGA GTT AGC CTA...... → ......AGT CGA TGG TTA GCC...... (A) The mutation occurs in the third position of a codon so it is likely to be a silent mutation because of the Wobble effect. (B) It leads to frameshift so the downstream amino acid sequence will alter and the protein is unlikely to be functional. (C) It results in premature termination of translation so a truncated polypeptide will be produced. (D) A longer polypeptide will be made but the protein might still be functional. (E) It changes the single amino acid, which may or may not cause a problem.

3. What is the purpose of the inverted repeats at the ends of DNA-based transposons? (A) The inverted repeats are recognized by enzymes that move the elements. (B) The inverted repeats are the sites of transfer. (C) The inverted repeats are recognized by restriction enzymes that cut out the transposon. (D) The inverted repeats are magnets for nucleases. (E) The inverted repeats protect transposons from degradation.