《今日食品科学》课程期末考试评分标准及标准答案.

1、北京联合大学应用文理学院第1页共 6 页今日食品科学课程期末考试评分标准及标准答案（2007 2008 学年 第 1 学期）生物技术（现代食品分析技术）专业 20062006 年级本科 专科口 A A 卷 B B 卷口 C C 卷口开课单位：生物学系班级或班数：2006级生物技术（现代食品分析技术）专接本1、2班 命题人：惠伯棣、中译英（本大题共 2020 个小题，每小题 1 1 分，共 2020 分）1、转基因生物GMO2、体外in vitroo尺&尺&3、等等etc.4、即i.e.5、烧杯Beaker6、烧瓶Flask7、圆/平底烧瓶Rou nd/Plai n-bottom flask8、

2、抽滤瓶Filter flask9、锥形/三角瓶Con ical flask10、试管Test tube11、离心管Cen trifuge tube12、洗眼器Eye washer13、试验服Lab coat14、量筒Volumetric/Graduated cyli nder15、布氏漏斗Buch ner funnel16、塑料洗瓶Plastic wash bottle17、吸耳球Pipette bulb18、滴管Dropp in g/B. pipette19、插销Power plug20、插座Electr onic socket二、选择填空（本大题共 4 4 个小题，1010 个填空，每个填

3、空 1 1 分，共 1010分）请选择一个正确答案填入每题的空中:21、 After a molecular biologist at a pharmaceutical company has identifiedahuma n gene that codes for a valuable product - a (c) substa nee called prote in V that kills certa inhuma n viruses, he wan ted to set up a system for making large amounts of the (a) so that

4、the (b) can bemanu factured on a large scale.北京联合大学应用文理学院第2页共 6 页a. geneb. DNAc. hypotheticald. virus22、 In step A, the biologist should isolate two kinds of DNA: the bacterial (a) that will serve as the (b)and the huma n DNA containing the protei n-V gene, called gene V. In this experiment, the DNA

5、containing the gene of interest comes fromhumantissue cells that have been growingin laboratory culture. The plasmidno rmally comes from (d).a. plasmidb. vectorc. virusd. the bacterium E. coli23、 In step B, the researcher treats both the plasmid and the human DNA with the same restriction(a). An enz

6、yme is chosen that cleaves the plasmid in only one place. The huma n DNA, with thousands of restrict ion sites, is cut into many (b),one of which carries the protein-V gene. In making the cuts, the restriction en zyme creates (c) endson both the huma n DNA fragme nts and the plasmid.a. en zymeb. fra

7、gme ntsc. stickyd. round24、 Biologists have identified about (b) species of living organisms from Nature.a. 4.1 millio nb. 1.5 millio nc. 2.3 millio nd. 8 millio n三、完形填空(本大题共 1 1 个小题，5 5 个填空，每个填空 2 2 分，共 1010分)25、 Most of a bacteriums DNA is found in a single bacterial chromosome, which_is a closed

8、loop of DNA with associated proteins. A bacterial chromosome is actually hun dreds oftimes Ion ger tha n the cell; it fits in side because it is highly folded. DNA is able to be transferredbetween bacteria following three ways. (a) Intransformation, a bacteria cell takes up a piece of naked DNA from

9、 its surro undin gs, (b) Tran sduction is the tra nsfer of a piece of cellular DNA from onecell to ano ther in side a phage. (c) In conjugation - a sort of mat ing - DNA istransferreddirectly from one bacterium to another via a bridge that formsbetwee n them.北京联合大学应用文理学院第3页共 6 页四、简答题(本大题共 2 2 个小题，4

10、4 个问题，每个问题 5 5 分，共 2020 分)阅读下文，并根据文中内容简要回答下列问题：26、Science seeks natural causes for natural phenomena. This limits the scope of scie nee to the studyof structures and processes that we can observe and measure, either directly or in directly with the helpof tools such as microscopes that exte nd our s

11、en ses. This depe ndence on observati ons that otherpeople can con firm demystifies n ature and dist in guishes scie nee from belief in the super natural.Science can n either prove nor disprove that an gels, ghosts, deities, or spirits, both ben evole nt andevil, cause storms,rain bows,ill nesses, a

12、nd cures, for suchexplanationsare outside the bounds of scienee.Verifiableobservationsandmeasureme nts are the data of discovery scie nee. In our quest to describe n ature accurately, wediscover its struct ure. In biology, discovery scie nee en ables us to describelife at its manylevels, from ecosys

13、tems down to cells and molecules.Darwinscareful description of the diverse plants and animalshe collected inSouth America is an example of discovery scie nee, sometimes called descriptive scie nee. A morerecent example is the seque ncing of the huma n geno me; its not really a set of experime nts, b

14、ut adetailed dissect ion and descripti on of the gen etic material.Discoveryscieneecan lead to importantconclusionsbased on a type of logiccalledinductivereasoning.An inductive conclusion is a generalizationthatsummarizes many con curre nt observati on s. All orga ni sms are made of cells is an exam

15、ple. That inducti on was based on two cen turies of biologists discoveri ng cells in every biological specimenthey observed with microscopes. The carefulobservatio ns of discovery scie nee and the in ductive con clusi ons they sometimes produce are fundame ntal to our un dersta nding of n ature.Ques

16、ti on 1:Somethi ng can not be proved by scie nee. What are examples?An swer:For example:an gels (1 point)ghosts (1 point) deities (1 point) spirits (1 poi nt) both ben evole nt and evil (1 poin ts)Questio n 2:What dose the data of discovery scie nee usually in elude?An swer:The data of discovery sci

17、e nee usually in elude:Observati ons (3 poin ts)Measureme nts(2 poin ts)Questio n 3:How can an in ductive con clusi on be made?An swer:Logically, an in ductive con clusi on is made accord ing to followi ng processes:1 To summarize many con curre nt observati ons (3 poin ts)2 To draw con clusi on fro

18、m those (2 poin ts)27、An esse ntial tool of DNA tech no logy, gel electrophoresis is a method for sorting北京联合大学应用文理学院第4页共 6 页macromolecules - proteins or nucleic acids - primarily on the basis of their electric charge and size. Forexample, we would use gel electrophoresis to separate the various DNA

19、 molecules in three differentmixtures at the same time. A sample of each mixture is placed in a well at one end of a flat, rectangular gel, a thin slab of jellylike material. The gel is supported by two glass plates. A n egativelychargedelectrode is the n attachedto the DNA-c on tai ning endof the g

20、el and a positiveelectrode to the other end. Because the DNA molecules have a n egative charge owing to theirphosphategroups,they move throughthe gel to positive pole.However, the Ion ger DNA molecules are held back by the molecules of the gel, so they move moreslowly, and thus not as far in a given

21、 time period, as the shorter DNA molecules. When the current isturned off, we see a series of bands in eachla ne of the gel. Each band con sists of DNA molecules of one size.Questi on 4:What is the practical process of DNA electrophoresis?An swer:The process usually in cludes:Gel preparati on (1 poi

22、nt)Sample loadi ng (1.5 poi nts)Running sample (1.5 poin ts)Result observation (1 point)五、回答问题(本大题共 1 1 个小题，2 2 个问题，每个问题 1010 分，共2020 分)阅读下文，并根据文中内容回答下列问题：28、The celebrated partnership that determined the structure of DNA began soon after the23-year-old Wats on journ eyed to Cambridge Uni versity, w

23、here Crick was study ing protein structurewith a tech nique called X-ray crystallography. While visit ing the laboratory of Maurice Wilk ins at Kings College in London, Wats on sawan X-ray crystallographic photograph of DNA, produced by Wilkinss colleague Rosali nd Fran kli n.The photograph clearly

24、revealed the basic shape of DNA to be a helix (spiral). On the basis of Watsons later recollectio n of the photo, he and Crick deduced that the diameter of the helix was uniform.The thickness of the helix suggested that it was made up of two pol y-n ucleotide stra nds - in otherwords, a double helix

25、.Using wire models of the n ucleotides, Wats on and Crick bega n trying to con struct a double helix thatwould conform both to Franklins data and to what was then known about the chemistry of DNA. Afterfaili ng to make a satisfactory model that placed the sugar-phosphate backb onesin sidethedouble h

26、elix, Wats on triedputti ng the backb ones on the outside and forcing the n itroge nous bases to swivel to the interior of themolecule. It occurred to him that the four kinds of bases might pair in a specific way. This idea ofspecific base pairing was a flash of in spirati on that en abled Wats on a

27、nd Crick to solve the DNApuzzle.At first, Wats on imagi ned that the bases paired like with like - for example, A with北京联合大学应用文理学院第5页共 6 页A, C with C. But thatkind of pairi ng did not fit withthe fact con sisted of twointertwined polynucleotide chains, with hydrogen that the DNA molecule has a unifo

28、rm diameter. An AApair (made of double-ringed bases) would be almost twice as wide as a CC pair, causingbulges inthe molecule. It soon becameapparent that a double-ringed base must always be paired with a single-ringed base on the oppositestra nd. Moreover, Wats on and Crick realized that thein divi

29、dual structuresof the bases dictated the pairi ngs eve n more specifically.Each base has chemical side groups that can best form hydroge n bonds with one appropriate partner.Ade nine can best form hydroge n bonds with thy mine, and gua nine with cytos ine. In the biologistsshortha nd, A pairs with T

30、, and G pairs _ with C._A is also said to be compleme ntary to T, and G to C.Wats on and Cricks pairi ng scheme not only fit what was known about thephysical attributes and chemical bonding of DNA, but also explained some data obta ined several yearsearlier by America n biochemist Erwin Chargaff. Ch

31、argaff and his co-workers had discovered that theamount of adenine in the DNA of any one species was equal to the amount of thy mine and that theamount of gua nine was equal to that of cytos ine. Chargaffs rules, as they are called, are expla ined bythe fact that A on one of DNAs polynucleotide chai

32、ns always pairs with T on the other polynu cleotidecha in, and G on one cha in pairs only with C on the other chain.Although the Wats on-Crick base-pairi ng rules dictate the side-by-side comb in ati ons of n itroge nousbases that form the rungs of the double helix, they place no restrictions on the

33、 sequence of nucleotidesalong the length of a DNA stra nd. In fact, the seque nce of bases can vary in coun tless ways. Conseque ntly, it is not surpris ing that the DNA of differe nt species, which have differe nt gen es, havediffere nt proporti ons of the bases in their DNA.In April 1953, Wats ona

34、nd Crick shook the scie ntific world with a succi net,two-page announ ceme nt of their molecular model for DNA in the jour nal Nature.Few milestones in the history of biology have had as broad an impact as their double helix, with its ATand CG base pairi ng.The Wats on-Crick model gave new meaning t

35、o the words gene and chromosome - and to thechromosome theory of in herita nce. With a complete picture of DNA, we can see that the geneticinformation in a chromosome must be encoded in the北京联合大学应用文理学院第6页共 6 页nu cleotide seque nee of its DNA molecule. The structure of DNA also suggests a molecular expla nation for lifes unique properties of reproduct ion and in herita nee, as we see n ext.Questi on 1:What was major tech nique applied to discover the 3-D structure ofDNA? What was the major application of this technique before DNA elucidati on? Wasth