103年 - [非官方正解]103 長庚大學_研究所碩士班(含碩士在職專班)招生考試_生物醫學研究所碩士班 :分子生物學#126186

1. Which of the following is not present in the core RNA polymerase? (A) β (B) β' (C) σ (D) both ẞ and σ

2. Which of the following characteristics is   not   a characteristic of a G protein? (A) They bind GMP for activation. (B) They have intrinsic GTPase activity. (C) Binding of GTP activates their function. (D) Cleavage of bound GTP to GDP inactivates them.

3. Which of the following is not necessary for retroviral insertion into the host genome? (A) RNA polymerase II (B) retroviral pol gene (C) viral protease (D) RNase H

4. Which of the following is the correct order of chromatin folding? (A) nucleosome formation, 30 nM fiber formation, radial loop structure (B) radial loop structure, 30 nM fiber formation, nucleosome formation (C) 30 nM fiber formation, nucleosome formation, radial loop formation (D) nucleosome formation, radial loop formation, nucleosome formation

5. The three-dimensional arrangement of the E. coli 16S rRNA closely resembles that of (A) the 30S ribosomal subunit (B) the 50S ribosomal subunit (C) the 70S ribosome (D) tRNA

6. Which of the following techniques was key in demonstrating the presynapsis and synapsis steps of homologous recombination? (A) exonuclease digestion (B) DNA footprinting (C) Southern Blot (D) electron microscopy

7. Which strategy can be used for determining the half-life of protein? (A) Mass spectrometry (B) Two-dimensional electrophoresis (C) Pulse-chase labeling (D) Western blotting

8. Which sequence signature determines the initiation site of translation in bacteria? (A) TATA-box (B) Kozak sequence (C)Shine-Dalgarno sequence (D) 5'-capping region

9. Which statement is correct about ribosome-mediated protein translation in bacteria? (A) The mRNA must be translated after the mRNA is completely transcribed. (B) The aminoacyl-tRNA enters ribosome through P site. (C) The IF-1 binds to A site to inhibit premature binding of aminoacyl-tRNA. (D) The specific sequence element is not required for translation initiation.

10. The lac repressor protein binds to (A) lactose and DNA. (B) RNA polymerase. (C) RNA polymerase and DNA. (D) beta-galactosidase, permease, and transacetylase.

11. The term "satellite" DNA refers to (A) extrachromosomal DNA fragments that are found close to (orbiting) the full-length chromosomes (B) mitochondrial DNA, which is circular in nature (C) long tandem repeats of simple DNA sequences (D) mobile DNA elements such as transposons and insertion sequences

12. What's a snRNP? (A) a nuclear complex of proteins and catalytic RNA (B) a particle required for recognition of the N-terminal signal sequence at the beginning of proteins destined for the cell membrane (C) an enzymatic complex required for transcription initiation in eukaryotes (D) none of above

13. Which of the following best describes thymine dimers? (A) intrastrand crosslinks induced by UV radiation (B) most commonly produced through oxidative damage to DNA, which is caused by the by-products of mitochondrial respiration (C) recognized by MutS and excised by MutH, when MutH is activated by MutL (D) byproducts of DNA replication, formed when one dTTP molecule is mistakenly linked to another rather than to the 3' end of the growing strand

14. A mutation in the lac operator that prevents it from serving its normal function will result in (A) expression of the operon even in the absence of lactose (B) repression of the operon even in the presence of lactose (C) expression of the operon even in the presence of glucose (D) repression of the operon even in the absence of glucose

15. Topo II is important in DNA replication because... (A) it induces positive supercoils ahead of the replication fork (B) it induces negative supercoils, facilitating unwinding of the DNA helix (C) it separates the two template strands from each other, providing a single-stranded template for DNA polymerase (D) topo II is not important for DNA replication, only topo I is required

16. A circular 11-nm chromatin fiber contains 100 nucleosomes. If this chromatin fiber are depleted of histone proteins and treated with an endonuclease to produce one single-strand break, what would the DNA look like? (A) a relaxed circular DNA duplex containing about 20,000 base pairs (B) a relaxed circular DNA duplex containing about 2,000 base pairs (C) a supercoiled DNA containing about 100 negative supercoils (D) a supercoiled DNA containing about 100 positive supercoils

17. The base composition of nucleic acids isolated from a unknown virus was found to contain 20% A,30% T, 30% G and 20% C. The nucleic acid of this virus is likely: (A) single-stranded RNA (B) double-stranded DNA (C) single-stranded DNA (D) double-stranded RNA

18. Which activity of bacterial DNA polymerase is used for editing (proof-reading) (A) 3' to 5' exonuclease (B) 5' to 3' exonuclease (C) primase (D) polymerization activity

19. A mutation that produces a temperature-sensitive phenotype is generally caused by: (A) base-pair substitution (B) macro-deletion (C) frameshift mutation (D) translocation

20. Which of the following structures is involved in the protection of eukaryotic chromosome from end-to-end fusions: (A) centromere (B) nucleolus (C) telomere (D) introns

21. In homologous recombination in E. coli, which protein binds to Holliday juncture with high affinity: (A) RecA (B) RuvA (C) RecBCD (D) RecFOR

22. The DNA isolated from two organisms A and B was found to contain unique sequence (i.e., no repetitive sequences). The Cot1/2 values for A- and B-DNA were 20 and 2 M s, respectively. These results suggest that: (A) the size of A-DNA is ten times larger than B-DNA. (B) A-DNA is circular and B-DNA is linear. (C) the sizes of A-DNA and B-DNA are the same. (D) the size of B-DNA is ten times larger than A-DNA.

23. One major problem of replicating linear DNA is that (A) the replicated DNA duplexes form catenane (B) the ends of linear DNA cannot be completely replicated (C) the replicated DNA duplexes are covalently linked (D) none of above

24. "DNase protection" is a technique used to identify: (A) the position of a intron. (B) the position of a exon. (C) a region of RNA that has been deletion. (D) the specific binding site of a repressor, polymerase, or other protein on the DNA.

25. The catalytic activity of ribozymes would be depended on: (A) correct base sequence (B) correct interaction with protein (C) correct secondary structure (D) all of the above

26. HIV infection would be treated with AZT (3'-azido-2',3'-dideoxythymidine) because AZT acts in HIV-infected cells by: (A) increasing GTP production. (B) blocking free radical synthesis. (C) inhibiting reverse transcriptase. (D) inhibiting apoptosis.

27. Centromere is (A) the chromosomal region that is the point of attachment of the mitotic spindle. (B) the chromosomal region that bind to several histone protein (C) the promoter region that bind to transcription factor (D) the 3' UTR region binging to miRNA

28. Which RNA is least or not involved in translation? (A) rRNA (ribosomal RNA) (B) tRNA (transfer RNA) (C) mRNA (messenger RNA) (D) snRNA (small nuclear RNA)

29. Which description is not correct for mRNA of eukaryotes? (A) The coding sequences are disrupted in primary mRNA (B) Introns are brought together by splicing in mature mRNA (C) Polyadenylation of primary mRNA at 5'-end takes place in nucleus (D) Polyadenylation of primary mRNA at 3'-end takes place in nucleus

30. Which sequences are removed in mature mRNA of chicken ovalbumin gene? (A) intron (B) exon (C) polyadenylation sequences (D) cap sequences

31. What is used to break intron/exon junction by RNA catalyzed splicing of RNA in protozoan Tetrahymena thermophila? (A) guanosine 3'OH (B) adenosine 2'OH in intron (C) small nuclear ribonucleoproteins (snRNPs) (D) endonuclease and ATP

32. 7-methylguanosine is added to the 5' end of almost all eukaryotic mRNAs in 5',5'-triphosphate linkage (A) at transcription initiation (B) at transcription elongation (C) after transcription (D) none of above

33. Which sequence at the 3'-untranslated region is involved in polyadenylation and regulation of mRNA stability of lung cells? (A) AAAAAU (B) AAUAAA (C) UUUUUA (D) UUAUUU

34. Which description is not correct for the flow of genetic information? (A) DNA to RNA by RNA polymerase (B) RNA to DNA by reverse transcriptase (C) RNA to RNA by reverse transcriptase (D) RNA to protein by ribosome-associated translation

35. Rous sarcoma virus genome is indicated below. Which gene is not necessary for the maintenance of the life cycle of this RNA virus?
(A) gag (for packing genome) (B) pol (for genome replication) (C) env (for packing virus particle) (D) src (for oncogenesis)

36. Which description   not   correct for telomerase? (A) it is a specialized reverse transcriptase (B) its activity is important for maintenance of telomere or chromosome ends (C) its contains RNA as template for extension of chromosome DNA at end (D) loss of telomerase is cancer-prone

37. Which description is   most   appropriate for Sp1, a transcription enhancer-binding protein in transcription? (A) its binding is position-independent (B) its binding is orientation-independent (C) its binding is position-dependent and orientation-dependent (D) its binding is position-independent and orientation-independent

38. Which description is   most   appropriate for RNA interference (RNAi)? (A) it involves the control of gene expression (B) it down-regulates gene expression through inhibiting translation (C) it down-regulates gene expression through enhancing mRNA degradation (D) all of above

39. If an mRNA was specifically localized at one side of the cell cortex, what would not be the mechanism for this localization? (A) mRNA was only transcribed at one side of the cell (B) at the other side of the cell, mRNA was degraded rapidly (C) an anchoring protein which binds to the 3'UTR of the mRNA was localized at one side of the cell cortex (D) mRNA was directly transported towards this side of cell

40. How do you visualize the localization of protein in cells? (A) RNA in situ hybridization (B) Western Blotting (C) Proteomic analysis (D) Immunofluorescent staining

二、問答題
1. Draw a diagram of the scanning model of translation initiation. Present evidence that a scanning ribosome can bypass an AUG and initiate at a downstream AUG. 

2. How do we know that mRNAs are read in the 5'→ 3' direction? 

三、翻譯題
The template strand of the DNA is copied during transcription, and its sequence is the complement of the RNA transcript. The coding strand of the DNA has the same sequence as the RNA transcript (except for T in the DNA and U in the RNA). Hence, for example, the start codon for transcription is 5'-ATG in the coding strand of the DNA and 5'-AUG in the mRNA. By convention, gene, promoter, and regulatory sequences in DNA are written as they appear in the coding strand.