7. Tautomers are isomers of organic compounds that readily interconvert by a chemical reaction called tautomerization. Which of the following tautomerisms does exhibit in the oxo group of purines and pyrimidines?
(A) lactam-lactim
(B) amide-imidic acid
(C) amine-imine
(D) keto-enol

複選題3. Which descriptions of the differences between eukaryotic and prokaryotic transcription are wrong? (A) Eukaryotic transcription occurs in the nucleus. (B) The 28S, 18S, 5.8S, and 5S rRNAs of eukaryotes are formed from one primary transcript. (C) There is no definite phase for prokaryotic transcription occurrence. (D) The eukaryotic transcriptional unit has one or more genes (polycistronic). (E) A single RNA polymerase of prokaryotes synthesizes all three types of RNA (mRNA, tRNA, and rRNA).

複選題4.How do eukaryotes generate various isoforms of RNA transcript from one gene? (A) Selective splicing (B) Alternative 5' donor site (C) Alternative 3' acceptor site (D) Alternative polyadenylation site (E) Different RNA polymerases

複選題5. Which descriptions of ribozyme are right? (A) Ribozyme is a protein. (B) Ribozyme is an RNA. (C) The substrate of ribozyme is proteins. (D) The substrate of ribozyme is DNA. (E) The substrate of ribozyme is RNA.

6. Glucose can form 16 isomers. Mannose and galactose are glucose's: (A) D and L isomers (B) Epimers (C) Alpha and beta anomers (D) Aldose-ketose isomers

8. Which of the below is NOT involved in intron removal and the processing of mRNA precursors into mRNA? (A) U2 snRNA (B) U3 snRNA (C) U4 SRNA (D) U6 snRNA

9. Which one of the following descriptions about mutations is WRONG? (A) An adenosine replaced by a cytidine is a "transversion" mutation. (B) An adenosine replaced by a guanosine is a "transition" mutation. (C) A nonsense mutation results in a different amino acid being inserted in the protein. (D) Silent mutation means a change at the DNA level that does not result in any change of amino acid in the encoded protein.

10. Which of the following product will be synthesized in platelets and upon release cause vasoconstriction and platelet aggregation? (A) Thromboxanes (B) Prostacyclins (C) Leukotrienes (D) Lipoxins

11. Prostanoids are synthesized by: (A) Pentose phosphate pathway (B) B-oxidation pathway (C) Lipoxygenase pathway (D) Cyclooxygenase pathway

12. In the lac operon, the CAP (cyclic AMP activator protein)-cAMP complex functions as: (A) A positive regulator (B) An operator (C) A repressor (D) All are wrong

13. The transcribed sequences complementary to the coding sequences above are:  5'-ACTGTATCGGAT-3' (coding)  3'-TGACATAGCCTA-5' (A) 5'-ACTGTATCGGAT-3' (B) 5'-ACUGUAUCGGAU-3' (C) 5'-ATCCGATACAGT-3' (D) 5'- AUCCGAUACAGU-3'