110年 - 110 國立中山大學碩士暨碩士專班招生考試_生科系碩士班/乙組:分子生物學#106072

科目：研究所、轉學考(插大)◆分子生物學 | 年份：110年 | 選擇題數：50 | 申論題數：0

試卷資訊

所屬科目：研究所、轉學考(插大)◆分子生物學

選擇題 (50)

1. DNA-binding proteins primarily recognize a specific sequence of double-stranded DNA through_________. (A) interactions with the exposed chemical groups in the DNA sugar-phosphate backbone (B) interactions with the exposed chemical groups in the minor groove of the DNA (C) interactions with the exposed chemical groups in the major groove of the DNA (D) attraction between the protein and negative charges on DNA

2. Which one of the following statements about the structure of RNA is NOT true? (A) RNA is capable of forming secondary structure. (B) RNA is capable of forming tertiary structure. (C) RNA is capable of forming pseudoknots. (D) RNA is capable of forming B-sheets.

3. Consider an experiment in which nucleic acids are separated using agarose gel electrophoresis. In the gel you load the following samples:
Lane 1: a population of linearized 3000-bp double-stranded DNA (dsDNA) molecules.
Lane 2: a population of circular 3000-bp double-stranded DNA (dsDNA) molecules
Which population of nucleic acids would most likely migrate through the gel fastest, and in which direction through the gel will these molecules migrate? (A) The linearized dsDNA would most likely migrate faster than the circular dsDNA. AlI DNA molecules would migrate toward the positive end of the gel. (B) The linearized dsDNA would most likely migrate faster than the circular dsDNA. AIl DNA molecules would migrate towards the negative end of the gel. (C) The circular dsDNA would most likely migrate faster than the linearized dsDNA. All DNA molecules would migrate toward the positive end of the gel. (D) The circular dsDNA would most likely migrate faster than the linearized dsDNA. All DNA molecules would migrate toward the negative end of the gel

4. Which of the following bioinformatics analyses involves scanning sequences in the genomes of related organisms to identify conserved non-coding regions, which may represent unknown regulatory elements? (A) BLAST (B) VISTA (C) genome annotation (D) genome editing

5. In a linear eukaryotic chromatin sample, which of the following strands is looped into domains by scaffolding? (A) the 30-nm chromatin fiber (B) the metaphase chromosome (C) DNA with H1 only (D) the 10-nm chromatin fiber

複選題
6. Which of the following statements is true about histones? (A) The mass of histone in chromatin is approximately nine times the mass of DNA. (B) The carboxyl end of each histone extends outward from the nucleosome and is called a "histone tail." (C) Histones are found in mammals, but not in other animals or in plants or fungi. (D) Histone H1 is not present in the nucleosome bead； instead, it draws the nucleosomes together.

7. Why do histones bind tightly to DNA? (A) Histones are highly hydrophobic, and DNA is hydrophilic. (B) Both histones and DNA are strongly hydrophobic. (C) Histones are covalently linked to the DNA. (D) Histones are positively charged, and DNA is negatively charged.

8. Why might they be conducting such an experiment? (A) to find the location of this gene in the human genome (B) to collect population data that can be used to assess natural selection (C) to collect population data that can be used to study genetic drift (D) to find which of the students has which alleles

9. Their next two steps, in order, should be (A) electrophoresis of the fragments, followed by Southern blotting using a probe. (B) electrophoresis of the fragments followed by autoradiography. (C) use of a ligase that will anneal the pieces, followed by Southern blotting. (D) use of a fluorescent probe for the gene sequence, then electrophoresis.

10. In recombinant DNA methods, the term vector can refer to (A) a DNA probe used to identify a particular gene. (B) a Single nucleotide polymorhism marker. (C) a plasmid used to transfer DNA into a living cell. (D) the sticky end of a DNA fragment.

11. Double-stranded DNA absorbs less UV light than single-stranded DNA because: (A) base stacking in double-stranded DNA increases the absorbance of white light and causes a decrease in the amount of UV light it can absorb. This decrease in UV absorbance is called the hyperchromic effect. (B) the bases are on the inside of the helix, inaccessible to the UV light in double-stranded DNA. (C) in single-stranded DNA the bases are not interacting, which adds to the light already absorbed by the pentose rings. (D) of the hypochromic effect that results when hydrogen bonding and base stacking in double- stranded DNA limits resonance in the aromatic rings of the bases.

12. A genome is … (A) All of the DNA in a cell. (B) A haploid set of chromosomes plus one copy of any organelle DNA present. (C) A haploid set of chromosomes. (D) A diploid set of chromosomes.

13. DNA microarrays have made a huge impact on genomic studies because they (A) dramatically enhance the efficiency of restriction enzymes. (B) can be used to introduce entire genomes into bacterial cells. (C) allow the expression of many or even all of the genes in the genome to be compared at once. (D) allow physical maps of the genome to be assembled in a very short time.

14. Which of the following best describes the complete sequence of steps occurring during every cycle of PCR?
1. The temperature decreased for primers hybridize to the target DNA.

2. The reaction mixture is heated to a high temperature to denature the double-stranded target DNA.
3. Fresh DNA polymerase is added.

4. DNA polymerase extends the primers to make a copy of the target DNA. (A) 3.4.2 (B)3,4,1,2 (C) 2,3,4 (D) 2,1,4 (E) 2,1,3,4

15. Which of the following modifications is least likely to alter the rate at which a DNA fragment moves through a gel during electrophoresis? (A) neutralizing the negative charges within the DNA fragment (B) altering the nucleotide sequence of the DNA fragment (C) methylating the cytosine bases within the DNA fragment (D) increasing the length of the DNA fragment

16. At a specific area of a chromosome, the sequence of nucleotides below is present where the chain opens to form a replication fork: 3' C C T A G G CT G CA AT C C 5' An RNA primer is formed starting at the underlined T (I) of the template. Which of the following represents the primer sequence? (A) 3' G CCTAGG 5' (B)5' GCCUAGG 3' (C)5'ACGTTAGG3 (D)S' ACGUUAGG3'

17. Which of the following methods is effective for separating proteins on the basis of their net charge? (A) ion-exchange chromatography (B) gel-filtration chromatography (C) affinity chromatography (D) polyacrylamide gel electrophoresis

18. A nucleosome forms hydrogen bonds with what part of the DNA? (A) with the phosphodiester backbone and with bases via the minor groove (B) only with bases via the major groove (C) only with bases via the minor groove (D) with the phosphodiester backbone and with bases via the major groove

19. Which of the following answer choices represents the correct evolutionary relationship between complexity of organisms and gene density (genes/Mb)? (A) Less complex organisms have increased gene density. (B) Less complex organisms have increased gene density. (C) Most organisms have a similar gene density. (D) There is no relationship between organismal complexity and gene density.

20. The "intergenic" parts of the human genome (i.e., the portion of the genome that does not encosde proteins or structural RNAs) consist of which types of DNA sequence (A) genome-wide repeats, microsatellite DNA, and regulatory sequences (B) introns, gene fragments, and pseudogenes (C) genome-wide repeats, pseudogenes, and microsatellite DNA (D) introns, regulatory sequences, and microsatellite DNA

21. Which of the statements best describes the mutational event pictured below?
Wild-type sequence ACC CAC UCU GGA UUU AAG GCA
Peptideencoded thr his ser gly leu lys ala

Mutant sequence ACC CAC UCU UGA UUU AAG GCA
Peptideencoded thr his ser stop phe lys ala (A) A transversion mutation leading to a nonsense codon (B) A frameshift mutation leading to a missense amino acid substitution (C) A transition mutation resulting in a silent amino acid substitution (D) A transition mutation leading to a nonsense codon (E) An insertion mutation resulting in a frameshift of the amino acid sequence

22.A mutant protein has been designated as G189A. What does this designation reveal about the mutation? (A) That a G nucleotide has been exchanged for an A nucleotide 189 bases from the 5' end of the coding region. (B) That a glycine in position 189 of the protein is now an alanine. (C) That an A nucleotide has been exchanged for a G nucleotide 189 bases from the 5' end of the coding region. (D) That a glycine is now in position 189 of the protein instead of an alanine. (E) That a nonsense mutation occurred at position 189 of the protein.

23.Which of the following is a correct pairing of a base to the product of its deamination? (A) Thymidine → uracil (B) Cytosine → thymine (C) Adenine → xanthine (D) 5-methylcytosine→ thymine

24. Which of the following are the results of external mutagens? (A) Template slippage during replication (B) Addition of bulky adducts to the DNA (C) Depurination (D) Recombination errors (E) Replication errors

25. What is the main difference between mismatch repair (MMR) in eukaryotes and prokaryotes? (A) Eukaryotes lack a functional Mut H and Dam methylase. (B) Eukaryotes have proteins homologous to MutS and MutH but not MutL. (C) Eukaryotes only repair the lagging strand. (D) Prokaryotic MMR can repair small loops of unpaired nucleotides, whereas eukaryotes cannot. (E) Both use exonucleases to eliminate the mismatched strand but eukaryotes only require 3'-5' exonucleases.

26. Why does mismatch repair not lead to mutation upon repair of heteroduplex DNA? (A) The incorrect base is recognized because it is methylated. (B) The strand containing the misincorporated base is methylated. (C) The strand containing the misincorporated base is not methylated. (D) The strand containing the misincorporated base is phosphorylated. (E) Actually, mismatch repair does lead to mutation about 50% of the time.

27. Why is transcription-coupled repair (TCR) considered particularly efficient when compared to nucleotide excision repair (NER)? (A) The exinuclease employed in TCR removes a smaller fragment containing the damage. (B) TCR targets transcriptionally active regions for repair over damage in less active parts of the genome. (C) It uses error-prone polymerases so it can move through damaged areas faster. (D) It directly repairs the damage rather than removing and replacing the damaged strand. (E) TCR requires less protein interactions.

28. Which of the following eukaryotic recombination proteins is structurally and functionally similar to RecA? (A) Spoll (B)RuvAB (C)RuvC (D) Dmel

29. Which of the following is NOT a component of the mating-type switch mechanism? (A) HO nuclease (B) Rad51 (C) Synthesis-dependent strand annealing (SDSA) (D)RecA

30. Which one of the following factors significantly contributes to the ability of eukaryotic cells to complete DNA replication during the short window of time offered by S phase? (A) The next round of replication begins before the cell exits S phase. (B) Eukaryotic DNA polymerases have dramatically increased processivity compared to DNA polymerases in organisms with smaller genomes. (C) Multiple origins of replication are activated per chromosome. (D) Origins of replication can initiate again after they have been replicated and before

31. Which of the following is NOT a step in non-homologous end joining? (A) Phosphorylation of the Ku70-Ku80 complex (B) Degradation of any single-strand overhangs or hairpins from the broken ends of the chromosomes to be repaired (C) Binding of the Ku70-Ku80 complex to the broken chromosome ends (D) Binding of a kinase and a nuclease to the Ku70-Ku80 complex on the DNA

32. Salmonella typhimurium can change flagella proteins to evade immune response by host systems. What is this process called? (A) Lysogeny (B) Bacterial transduction (C) Phase variation (D) Transposition

33. Which of the following will NOT result from site-specific recombination? (A) Inversion (B)Deletion (C) Insertion (D) Translocation

34. P1 bacteriophage can be used as an experimental vehicle to move genes from one cell to another because occasionally large pieces of host DNA are accidently packaged into phage heads. What is this process called? (A) Lysogeny (B) Bacterial transduction (C) Phase variation (D) Transposition

35. Which of the following mechanisms is used by retrotransposons? (A) Cut-and-paste transposition (B) Replicative transposition (C) Transposition via an mRNA intermediate (D) Bacterial transduction

36. The processivity of a DNA polymerase depends on all of the following actions, EXCEPT for__________. (A) interaction between the thumb domain of DNA polymerase and the DNA (B) association of the DNA polymerase with a sliding clamp (like eukaryotic PCNA) (C) interaction between the minor groove of DNA and the palm domain of the DNA polymerase (D) loss of the hydrogen from the 3'-OH of the primer due to interaction with a divalent metal ion associated with the palm domain of the DNA polymerase

37. Which of the following statements correctly describes the role of telomerase in eukaryotic cells? (A) It synthesizes the Okazaki fragment needed to prevent loss of genetic information at the 5' end of the chromosome. (B) It synthesizes new DNA (using a RNA template) at the 3' end of the chromosome. (C) It synthesizes new DNA (using a DNA template) at the 5' end of the chromosome. (D) It synthesizes DNA on both the 5' and 3' ends of the chromosome.

38. Which of the following components are required for integration of bacteriophage ~ genome into the host bacterial genome? (A) attB, attP, λInt, IHF (B) attB, attP, λInt, Xis (C) attL, attR, λ Int, IHF (D) attB, attP, λ Int

39. Upon the initial infection of a host cell by bacteriophage λ, the first two proteins produced from expression of the phage genome are: (A) cI and cII (B) N and cI (C) N and Cro (D) Cro and cl

40. The int/xis encoded enzyme of bacteriophage λ is required to: (A) excise the prophage from the host genome. (B) degrade phage mRNA during lysogenic growth. (C) bypass terminator structures downstream from the N and Cro genes. (D) combine multiple DNA segments to make new genes.

41. Ribosomal proteins that can act as translational repressors: (A) are not encoded by the same mRNA that they repress. (B) bind to a site on the mRNA near the start site of one gene in the operon. (C) bind to its mRNA with higher affinity than to the appropriate rRNA molecule. (D) bind to the mRNA when sensing that levels of r-protein are low relative to rRNA.

42. How does the RecA protein contribute to the increased expression of SOS genes? (A) RecA protein competes with LexA protein for binding to the operator sequences. (B) RecA protein binds to LexA protein bound to the operator, directly lowering the affinity of LexA protein for DNA. (C) RecA protein binds to free LexA protein, mediating the self-cleavage of the repressor. (D) RecA protein binding to the promoter region recruits RNA polymerase.

43.Which of the following is NOT a characteristic of a riboswitch? (A) They are structures that exist in the 5' untranslated region of some mRNA molecules. (B) They exert gene expression control only at the level of translation. (C) They physically bind to small-molecule metabolites. (D) Ligand-binding to the riboswitch can sequester the Shine-Delgarno sequence.

44. Which of the following is NOT true of the regulation of the arabinose operon? (A) CRP activates expression when bound to cAMP. (B) AraC protein recruits RNA polymerase when bound to arabinose. (C) Arabinose binds to AraC protein, decreasing its affinity for a DNA site near the promoter. (D) Arabinose binding alters the conformation of the dimerization domain of the AraC protein.

45. Catabolite repression of the lac operon restricts expression when: (A) glucose is absent. (B) lactose is absent. (C) glucose is present. (D) lactose is present.

46. The binding of______________ to the Lac repressor causes the protein to dissociate from the operator. (A) lactose (B) glucose (C) fructose (D) allolactose

47. Which of the following is NOT true of the imprinting of the mammalian gene for insulin growth factor-2 (IGF-2)? (A) CTCF binds to the methylated IGF2 gene insulator. (B) IGF2 gene is activated when the insulator is methylated. (C) The maternally inherited copy of IGF2 is normally repressed in egg cells. (D) The insulator of both the paternal and maternal IGF2 alleles lies between the promoter and the enhancer.

48. DNA microarrays have made a huge impact on genomic studies because they (A) dramatically enhance the efficiency of restriction enzymes. (B) can be used to introduce entire genomes into bacterial cells. (C) allow the expression of many or even all of the genes in the genome to be compared at once. (D) allow physical maps of the genome to be assembled in a very short time.

49. The upstream activator sequences (UASs) of yeast are analogous to____________ in higher eukaryotes. (A) Promoters (B) TATA boxes (C) operators (D) enhancers

50. The enzyme that cleaves the mRNA transcript targeted by siRNA is: (A) Drosha. (B) Dicer. (C) Argonaut. (D) RNase A.

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