35. Which one is NOT the marker of Epithelial-mesenchymal transition?
(A) N-cadherin
(B) E-cadherin
(C) vitronectin
(D) integrin
(E) Zebl

31. The functional activity of proteins can be modulated by protein modification. Which description is not true? (A) Mass spectrometry is a tool to identify protein modification. (B) Protein phosphorylation occurs at the residues of Ser, Thr, and Tyr. (C) Protein methylation occurs at the residues of Leu and Arg. (D) Histone acetylation results in gene activation. (E) Histone methylation would activate or repress gene expression.

32. Binding of hormone to a receptor tyrosine kinase causes all of the following except: (A) dimerization of the receptor. (B) autophosphorylation of the receptor. (C) activation of Ras through an interaction with GRB2 and Sos. (D) hydrolysis of GTP bound to Ras. (E) All of the above are incorrect.

33. Predict the consequences of a temperature sensitive mutation in which the phosphorylation of the b-catenin protein is blocked. Above the permissive temperature, (A) b-catenin levels will increase and b-catenin will be constitutively active. (B) b-catenin levels will increase and b-catenin will be inactive. (C) b-catenin levels will decrease and cells will be inactive. (D) b-catenin will remain decrease and cells will be more sensitive to Wnt signaling (E) b-catenin will remain constant but cells will be unresponsive to Wnt signaling.

34. Fully differentiated mouse fibroblasts can be reprogrammed or induced to form pluripotent stem cells when transfected with retroviral vectors expressing: 　 1. KLF4.2. c-MYC. 3. SOX2. 4. Ngn1 5. Oct4 (A) 1, 2, 3, 5 (B)1, 2, 3, 4 (C) 1, 2, 4, 5 (D) 1, 3, 4, 5 (Ε) 2, 3, 4, 5

36. Which statement listed below concerning general molecular biology techniques is correct? 1. Run-on transcription determines the translational rate. 　 2. Primer extension determines the start of transcription. 　 3. Southern blot determines if a probe is complementary to a DNA target. 　 4. Northern blot determines the size and abundance of a RNA. 　 5. Gel mobility shift assay determines whether a protein binds DNA. (A) 1, 2, 3, 4 are correct. (B) 1, 3, 4, 5 are correct. (C) 2, 3, 4, 5 are correct. (D) 1, 3, 4, 5 are correct. (E) All of above are correct.

37. What method can be used to functionally inactivate a gene without altering its sequence? 1. gene knockout 　 2. RNA interference 　 3. dominant negative mutation 　 4. CRISPR/Cas9 system (A) 1 and 2 are correct. (B) 2 and 3 are correct. (C) 2 and 4 are correct. (D) 1, 2 and 4 are correct. (E) All of above are correct.

38. Next generation sequencing is much more efficient than the Sanger method because: 　 1. It uses an RNA template instead of DNA. 　 2. It uses gel electrophoresis to resolve end-labeled strands of DNA. 　 3. It uses PCR amplification. (A)1 is correct (B) 2 is corrrect (C) 3 is correct (D) 1 and 3 are correct (E) All of above are correct

39. Compare the advantages and limitations of microarrays and Northern blots for analyzing gene expression. Which statement listed below is correct? 　 1. Microarrays allow a more global analysis of gene expression by analyzing thousands 　 2. Microarrays data analysis can reveal groups of known and unknown genes that are regulated in a coordinated fashion. 　 3. Northern blots allow the analysis of only a few genes at a time. 　 4. Northern blot can reveal the presence of multiple mRNAs from one gene locus that may be differentially expressed. The presence of multiple mRNAs could be missed by microarray analysis. (A) 1, 2, 3 are correct. (B) 1, 3, 4 are correct. (C) 2, 3, 4 are correct. (D) 1, 2, 4 are correct. (E) All of above are correct.

40. Which of the following best describes the function of reverse transcriptase? (A) It's involved in viral attachment to a host cell. (B) It uses an RNA template to make a double-stranded DNA. (C) It uses DNA to synthesize an RNA in the 3' to 5' direction. (D) It joins the gene segments that code for antibodies. (E) Its reaction products can be inserted directly into plasmid.

1. Which of the following pairs of bonds can rotate within a peptide backbone and the torsion angle of the latter is assigned as psi angle? (A)(B)(C)(D)(E)