資訊推薦

• 13. Histones are__________(A)Neutral(B)Positively charged(C) Negatively charged(D)Neutral with posit
• 14. Which of the following is not a common mode of histone modification in eukaryotes?(A)Methylation
• 15. The lactose repressor is encoded by__________(A)Lac-l(B)Lac-A(C) Lac-Y(D)Lac-Z
• 16.Which of the following can be extended by DNA polymerase?(A)a single strand DNA end in a deoxyrib
• 17. DNA Pol I is proteolytically cleaved to yield the__________ , which lacks 5'-3' exonuc
• 18.What is the causative agent in the formation of a cyclobutane thymine dimer?(A)benzo[a]pyrene(B)N
• 19.Which of the following is formed by oxidation of a DNA base?(A)uracil(B) 7-methylguanine(C) 8-oxo
• 20.What is an Okazaki fragment?(A)a small sectio on of DNA bound to the leading strand(B)a small sec
• 21. In DNA synthesis, the____________strand is synthesized in a fashion.(A) template; discontinuous(
• 22. Replication of DNA in E.coli occurs in what type of fashion?(A)directionality can change dependi
• 23.Which histone protein is associated with the linker DNA and therefore not actually part ofthe nuc
• 24. Which of the following statements about DNA methylation is NOT TRUE?(A)methylation plays a role
• 25.What technique is used to amplify portions of DNA, usually about 800 base pairs in size?(A)DNA se
• 26.The repair of a double-strand break can be accomplished by__________，whichrequires the Ku70/80 pr
• 27. DNA Pol I synthesizes new DNA with very high fidelity, due to its(A)high processivity.(B)3'
• 28. Synthesis of telomeres requires the enzyme_________， which is a type of_________.(A)telomerase,
• 29. Deamination of cytosine leads to the formation of__________.(A)thymine(B)uracil(C) 5-bromouracil
• 30. Which of the following describes the Holliday junction?(A)point where DNA base excision repair i
• 31. Huntington disease is caused by_________.(A)pyrimidine dimers(B) trinucleotide expansion(C) supp
• 32. How does RecA bring about strand exchange?(A)RecA acts as a helicase, unwinding DNA in localized
• 33.What enzyme is responsible for unwinding of the DNA ahead of the replication fork?(A)topoisomeras
• 34.Which of the following is the best description for primase?(A)an RNA-dependent DNA polymerase(B)
• 35.For a restriction enzyme with a 6-base recognition site, what is the average number of basepairs
• 36.EcoRI has a restriction site of GLAATTC while EcoRV has a restriction site ofGATVATC. Based upon
• 37. Which of the following describes the correct sequence of enzyme activity upon thelagging strand?