37. What is a TA vector and how is TA cloning done?

42. Please describe the molecular process (including all the molecules involved) of homologous recombination in E. coli.

43. Please describe the regulation for Tryptophan attenuation in prokaryote.

44. Please explain what is CRISPR and the application of CRISPR?

II. 簡答題 - essay questions 36. Which molecular biology method is the most reliable approach to examine the current status of SARS-CoV-2 infection? What kind of viral information is required for the assay? Please explain how CT value is determined and what it means.

38.(1) Please describe how post-transcriptional control of transferrin receptor (TfR) expression by cytosolic aconitase under high and low cellular iron levels.

(2)Please predict the outcomes if a mutation prevents aconitase from binding iron in the cell that contains abundant TfR mRNA.

(1)Please explain "polycistronic RNA"?

(2)Please explain the mechanism of "ribosomal frameshifting" for the translation of viral products of SARS-CoV-2.

40. Non-coding RNAs (ncRNAs) do not code for proteins. Column I lists ncRNAs. Match each one in column I to its correct description in Column II. Column I small cytoplasmic RNAs (scRNA) small nuclear RNA (snRNA) small nucleolar RNA (snoRNA) Column II A. RNAs that are present in the cytoplasm. B. One of many small RNA species confined to the nucleus； several of them are involved in splicing or other RNA processing reactions. C. A small nuclear RNA that is localized in the nucleolus.

(1)