(生物科技行業(yè)類)福建農林大學期末考試試卷參考答案

1、試題第3頁（共8頁）福建農林大學期末考試試卷參考答案2009 2010學年第 學期課程名稱：分子生物學 考試時間120分鐘專業(yè) 年級 班 學號 姓名題號一一得分評卷人簽字復核人簽字三四總得分得分 填空題（每空 0.5分，共10分）1、There are five types of DNA repair, include photo-reactivation repair,and error-prone repair.（切除修復；重組修復；錯配修復)2、The holoenzyme of E.coli RNA polymerase is, the core enzyme is made up o

2、f, while the factor has the ability to recognize specific binding sites. (00233 '(T； a 233'； 0-)3、The eukaryotes have a well-defined cell cycle.The phase are : G1,andM. (S; G2)4、Only one strand of a DNA duplex will be transcribed. So the RNA is identical in sequencewith another strand of the

3、 DNA which is called , and the template strand is .(有義鏈；反義鏈)5、In eukaryotes, mRNA processing includes the following steps: addition of at 5 ' end, addition at 3 ' end, remoof , joining together the ,And these take place in(M7G帽子結構；poly(A)尾巴；內含子；外顯子； 細胞核)6、The structure is a common secondary

4、structural reprensentation of tRNA（三葉草；L）molecules. The tertiary structure of tRNA molecules is 7、In the large 60S subunit of the eukaryote ribosome, there are rRNA, and rRNA, and rRNA. ( 5S; 5.8S; 28S)B 二、名詞解釋（每小題 2分，共30分）1、Promoter ： RNA聚合酶結合并起始轉錄的一段DNA序列。2、Semi-conservative replication :半保留復制，親代雙

5、鏈DNA以每條鏈為模板，按堿基配對原則各合成一條互補鏈，這樣一條親代DNA雙螺旋，形成兩條完全相同的子代 DNA螺旋，子代DNA分子中都有一條合成的“新”鏈和一條來自親代的舊鏈。3、Intron :真核生物DNA編碼序列中間隔的非編碼序列，它們也能被轉錄成RNA ,但在mRNA成熟加工中會被切除。4、Transversion ：在基因突變中，喋吟被喀咤所代替的現(xiàn)象，反之亦然。5、Gene recombination :指由于不同DNA鏈的斷裂和連接而產生的DNA片段的交換和重新組合，形成新的DNA分子的過程。因此，新的DNA分子中含有原來的兩個 DNA分 子的片段。6、Hybridizatio

6、n :不同來源的核酸單鏈通過堿基互補配對原則結合成雙鏈的過程。7、Transcription :以DNA為模板，在 RNA聚合酶的催化下，合成 RNA的過程。8、Proofreading activity :即DNA聚合酶的3' - 5'外切酶活性，當復制過程中插入錯 配堿基時該活性被激活，進而將錯配堿基切除。9、RNA processing ： RNA加工，前提 RNA轉變?yōu)槌墒?RNA的過程，發(fā)生在細胞核內。10、Triplet code :三聯(lián)體密碼，3個連續(xù)的核甘酸編碼一個氨基酸。11、Chaperone：分子伴侶，幫助蛋白質分子形成正確空間構象的輔助分子。12、Tra

7、ns-acting element:反式作用元件，指能直接或間接地識別或結合在各類順式作用元件核心序列上參與調控靶基因轉錄效率的蛋白質。13、Open reading frame：特定的核酸序列由一個起始密碼子（ AUG/ATG ）和三個終止密碼子組成，核酸序列能翻譯為蛋白質序列。14、Ribozyme：核酶，具有催化作用的RNA分子。15、Zinc finger ：鋅指，一種常出現(xiàn)在 DNA結合蛋白中的一種結構基元。是由一個含有 大約30個氨基酸的環(huán)和一個與環(huán)上的4個Cys或2個Cys和2個His配位的Zn2+構成,形成的結構像手指狀。|得分|三、單項選擇題（每小題1分，共15分）(D )

8、1、What is the percentage of A in a piece of RNA if the percentage of C is 30%?B. 20%A. 30%C. 60%D. Unable to calculate with the information provided.(D ) 2、Which of the following is NOT a function of RNA?A. It acts a template during translation.B. It is required for RNA splicing.C. It is essential f

9、or the structure of ribosomes.D. It attaches the correct amino acid to tRNA.(C ) 3、 Histones are found in close association with DNA. Which of the following statements is incorrect?A. Histone H1 is less evolutionarily conserved than core histones.B. A nucleosome is composed of 146 bp of DNA and a hi

10、stone octomerC. There are only four types of histonesD. Nucleosomes are evenly distribution within chromatin(B ) 4、The elongation of the lagging strand during DNA synthesis:A. In the 3 -5' ' directnB. Produces Okazaki fragmentsC. Polymerizes into the direction of fork movementD. Does not req

11、uire a template strandC ) 5、 Telomeres are found at the end of chromosomes and they are synthesized by telomerase. Which one of the following statements is correct?A. The function of telomerase is to directly elongate the leading strand during DNA replication.B. Telomers code for ribosomal RNA.C. Te

12、lomerase is an unusual enzyme made up of RNA template and protein.D. Telomerase is active in all cell types.C ) 6、 Which of the following is correct concerning transcription and DNA replication?A. Only transcription requires a primer.B. Transcription starts at the origin of replication.C. In DNA rep

13、lication, both the coding and template strands are copied.D. The entire genome is copied in transcription.D ) 7、 Which of the following statements describes a similarity between the structure ofDNA and RNA? In both DNA and RNA,A. the nitrogenous base uracil is found.B. there is a hexose sugar.C. the

14、 carbon 2 has an hydroxyl group.D . the nitrogenous base is attached to carbon 1.D ) 8、 Regulation of the trytophan operon involvesA. repression (at an operator)B. attenuationC. the concentration of free trytophanD. all of the aboveB ) 9、 Which of the following is not stop codon?A. TAAB. TATC. TAGD.

15、 TGAA ) 10 、 The Shine-Dalgarno sequence in mRNAs試題第 5 頁（共 8 頁）A. base pairs to the 3'-end of E. coli 16S rRNAB. base pairs to the 5'-end of E. coli 16S rRNAC. has a consensus sequence of YNCURACD. is located just downstream of the initiation codon( C ) 11、Which of the following is not bound

16、 to the aminoacyl-tRNA synthetase?A. amino acidB. tRNAC. GTPD. ATP( D ) 12、The ribosome scanning model for translation was proposed byA. P. SharpB. R. RobertsC. T. CechD. M. Kozak( D ) 13、Most nuclear mRNA introns begin with and end withA. U, GB. GU, NGC. AG, GUD. GU, AG( A ) 14、 Which of the follow

17、ing is the covalent linkage of ubiquitin molecule with the protein damaged?A. GlyB.LysC. LeuD.Thr( C ) 15、In nuclear mRNA splicing, the intron is released as aA. circular RNAB. linear RNAC. lariat RNAD. a " Y” RNAH四、問答題（45分）1、 Please illuminate the main content of central dogma and draw the ske

18、tch map. （8 points）DNA是生物遺傳的主要物質基礎。遺傳信息以特定的脫氧核甘酸序列儲存在DNA分子中（1分）。DNA能準確地自我復制（1分），并把遺傳信息轉錄到mRNA分子上（1分），然后通過 mRNA翻譯成為具有特定氨基酸順序的蛋白質（1分），由蛋白質行使各種生物學功能。Crick把這種遺傳信息的流動稱為分子遺傳的中心法則。后來人們又發(fā)現(xiàn)反轉錄病毒可以其RNA作為模板指導合成 DNA （1分）；某些病毒RNA可以進行自我復制，即以自身RNA為模板，合成子代 RNA （1分）。這些發(fā)現(xiàn)是對試題第5頁（共8頁）中心法則的補充和發(fā)展。RNA復制廣、轉錄翻譯VDNA I RNA蛋白

19、質（2 分）逆轉錄2、What is the operon? How the lac operon controls gene expression? （8 points）操縱子是原核生物基因表達調控的單位（1分），包括啟動子、操縱基因和一系列功能上相關的結構基因（1分）。沒有乳糖一 lacI編碼的阻遏蛋白具有活性一牢固結合到操縱基因。上一結合在啟動區(qū)的RNA pol不能通過一 Z、Y、A不能轉錄（和表達）（3分）加入乳糖一乳糖（誘導物）與阻遏蛋白結合一阻遏蛋白構象變化一阻遏蛋白從操縱基因上脫落一 RNA pol開始Z、Y、A基因的轉錄，表達一乳糖被利用（3分）3、Please write o

20、ut the enzymes and proteins required in prokaryotic DNA replication , andexplain their functions. （ 7 points）拓撲異構酶：消除 DNA超螺旋產生的阻力；（1分）解鏈酶：解開 DNA雙鏈，產生單鏈 DNA ; （1分）SSB:保護解開的DNA單鏈，避免復性；（1分）引物酶：合成RNA引物，為DNA聚合酶提供3'末端；（1分）DNA聚合酶III :延長DNA片段，是真正起復制作用的酶；（1分）DNA聚合酶I:負責切除引物并填補引物所在的缺口；（1分）DNA連接酶：連接岡崎片段。（1分

21、）4、What are the characters of expression vectors? （5 points）（1）能夠進行獨立于基因組的自我復制（1分）（2）容易從細胞中分離提取（1分）（3）含有多克隆位點，允許外源片段的插入 （1分）（ 4）含有至少一個選擇標記（ 1 分）（ 5）具有啟動子、終止子等表達元件（ 1 分）5、 Please illuminate the function of the cap structure of mature mRNA in 5（ 5 points ） emd.（1） 對 5外切核酸酶形成屏障，保護和穩(wěn)定轉錄產物（2 分）（2） 有助于前體mRNA 的剪接和轉運到細胞質（2 分）（3） 提高翻譯的效率（1 分）6、 Please illuminate the difference between the initial tRNA molecule and the tRNA Met in elongation in E.coli . （ 5 points）（ 1）只有起始tRNA 分子的蛋氨酸甲酰化，非甲酰化的fmet-tRNA 也能起始，但效率不高，因為甲?；桥ctRNA 分子結合的起始因IF2 的識別標志（2分）（ 2） tRNA