36. A microRNA (miRNA) is a small non-coding RNA, which can down-regulate mRNA expression levels. Please choose the correct statement about animal miRNA.
(A) It is transcribed by RNA polymerase I.
(B) It is 10-20 nucleotides in length single-stranded RNA.
(C) It is perfectly complementary to its mRNA targets.
(D) It is a ribonuclease.
(E) It forms a RISC complex to destabilize its mRNA targets.

32. Which one is NOT correlated with longevity? (A) high levels of plasma sphingomyelin (B) low levels of PUFA-containing triacylglycerols (C) high level of plasma cholesterol (D) tryptophan (E) high energy expenditure

33. Which one has asymmetric cell division? (A) Hepatocyte (B) Splenocyte (C) Intestinal epidermal cell (D) Stem cell (E) Skin cell

34. Which molecule does NOT participate in autophagy? (A) ULK1 (B) Beclin1 (C) LC3 (D) ATG7 (E) Caspase

35. The results of human genome project show that more than 98% of the human genomes are composed of non-coding DNA (ncDNA) which are never represented within the amino acid sequence of expressed proteins. Which description is incorrect? (A) About 20,000 human proteins have been annotated in databases, which is significantly larger than that of the fruit fly. (B) The extensive use of alternative pre-mRNA splicing in humans provides the ability to build a very large number of modular proteins. (C) Some ncDNAs contain genes for RNA molecules with important biological functions. (D) Transposable elements belong to ncDNAs, which account for at least 50% of the human genome. (E) Some ncDNAs contain intron, 5' UTR and 3'UTR.

37. Post-translational modifications modulate a protein activity. To study the functional effect of a protein phosphoprylated at Ser/Thr, we generate a non-phosphorylatable mutant by changing to AlA What amino acids are used for creating a phosphomimetic mutant? (A) Asp and Glu (B) Lys and Arg (C) Leu and Ile (D) Gln and Arg (E) Tyr and Phe

38. Which description is incorrect for chromatin-immunoprecipitation (ChIP) experiment? (A) It is for DNA-protein interaction. (B) Formaldehyde is used to crosslink DNA-protein only. (C) The genomic DNA has to shear into smaller fragments by sonication or nuclease digestion. (D) The specific antibody against the interested protein is to immunoprecipitate cross-linked DNA fragments. (E) The precipitated DNA regions are examined by quantitative PCR.

39. Induced pluripotent stem (iPS) cells are a type of pluripotent stem cell that are obtained by reprogramming somatic cells through artificial expression of key transcription factors including OCT4, KLF-4, SOX2, and c-MYC. What is incorrect? (A) These transcription factors promote self-renew. (B) They suppress differentiation-related gene expression. (C) They alter DNA sequences to regulate gene expression. (D)DNA methylation inhibitor could facilitate iPS cell formation. (E) Histone deacetylase inhibitor could induce iPS cell formation.

40. We are studying a transcription factor. What is incorrect? (A) Its mRNA expression is determined by northern blot. (B) Its protein expression is monitored by western blot. (C) Its target gene promoter is cloned from a cDNA library. (D) The promoter is ligated with luciferase gene for reporter assay. (E) The electrophoretic mobility shift assay is performed to display DNA-protein interaction.

1. Please choose the correct answer from the following descriptions: 1. Protein sectors are evolutionary units of three-dimensional structure. 2. The α-D-glucose and β-D-glucose interconvert in aqueous solution.  3. Lectin is the exoskeleton of insects. 4. β-Keratin is Gly and Pro rich. 5. The pl of histidine is around 6. (A) 1 and 2 are correct. (B) 1, 3 and 4 are correct. (C) 1 and 5 are correct. (D) 2, 3 and 4 are correct. (E) Only 4 and 5 are incorrect.

2. Which description is correct? (A) Lipopolysaccharide is a dominant feature of the outer membrane of the cell wall of gram-negative bacteria. (B) Trypsin could hydrolyze the "X-K" peptide bond. (C) Orthologous genes are presumed to have been derived by gene duplication followed by gradual changes in the sequences of both copies. (D) Collagen is full of α-helix structure and has Gly-X-Pro repeating sequence. (E) For naming the RS system, -CH2OH group has higher priority than -CHO group.