首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
外语
A、Climate. B、Instinct. C、Temperature. D、Salinity. B
A、Climate. B、Instinct. C、Temperature. D、Salinity. B
admin
2018-06-27
74
问题
I’ve mentioned how DNA has solved many mysteries in biology. And today I want to talk about how it might relate to hypothesis about the travels of the green turtle. [23] Every winter some green turtles make a 2,000 km journey from Brazil to Ascension Island in the middle of Atlantic, where they mate and lay eggs. But the question is why do they travel so far to lay their eggs? One researcher hypothesized that there are two parts to the explanation. One is natal homing, [24] the instinct that drives green turtles to always return to the beach where they were hatched. The second part has to do with continental drift, the theory that the positions of earth continents have changed considerably overtime. Brazil and Ascension Island were once much closer together, and continental drift drove them apart. But the turtles kept on going back to the island where they hatched. However another scientist questioned this explanation on the grounds that it would be very unlikely that conditions would allow generations of turtles over hundreds of millions of years to keep going back to the same nesting ground every single year. So, what is the connection to DNA? Well, there are groups of green turtles that nest in locations other than the Ascension Island. If green turtles always return to the place where they were hatched, then the turtles that have been going to the Ascension Island to nest would have been genetically isolated long enough to have DNA that was very different from the green turtles that nest elsewhere. But when scientists examined DNA from these turtles, their DNA wasn’t that different from the DNA of the turtles that go to Ascension Island. Do you have a shock? Well, we still don’t know the answer to the question about why a certain group of turtles go to Ascension Island, but [25] this study was a nice example of the usefulness of DNA analysis to biology.
1.How far do some green turtles travel to lay their eggs?
2.What drives green turtles to return to the beach according to the theory of “natal homing”?
3.What is proved in this study?
选项
A、Climate.
B、Instinct.
C、Temperature.
D、Salinity.
答案
B
解析
转载请注明原文地址:https://kaotiyun.com/show/lsH7777K
0
大学英语六级
相关试题推荐
PresidentBarackObama’spicktoheadtheEnvironmentalProtectionAgency(EPA),LisaJackson,hasspent20yearsasanenvironme
A、Heistoooldtoknowhowtorespecttheothers.B、Heistreatedunjustlybyallcustomers.C、Hedoesn’tknowhowtorespectt
A、Competitionisbecomingmorefierceandserious.B、Peopleunderestimatetheirattemptsandefforts.C、Itisnomoreshamefult
A、Stopexercising.B、Dosomesafeexercise.C、Doexerciselessfrequently.D、Doexercisewiththerapists.B讲座中提到如果你受伤了,和你的医生或治疗师
A、Studyinginaforeignenvironment.B、Livingfarawayfromfamily.C、Returningbacktohomecountry.D、Fittingintoaforeignc
A、Togotoschool.B、Totakeuniquepictures.C、Tovisithisrelatives.D、Tomakeexplorations.A
A、Howtosafeguardthecomputernetwork.B、Howtostealtopsecretfilesfromamilitarybase.C、Howtomakemoderndevicesbroa
GermanChancellor(首相)OttoVonBismarckmaybemostfamousforhismilitaryanddiplomatictalent,buthislegacy(遗产)includesman
秦始皇是中国历史上杰出的政治家、军事家。公元前221年,他统一中国,建立了历史上第一个统一的、多民族的、高度中央集权的(highlycentralized)国家——秦朝,并成为中国第一个皇帝,自称“始皇帝”。为加强统治,他实施了一系列的改革,如统一文字,
AreyourFacebookfriendsmoreinterestingthanthoseyouhaveinreallife?Hashigh-speedInternetmadeyouimpatientwithslo
随机试题
男性,50岁。无痛性全程肉眼血尿2周,尿细胞学检查发现有肿瘤细胞,诊断为膀胱癌。入院后行膀胱全切、回肠代膀胱术治疗。术后病人常独处,害怕家人探视,主诉不知如何护理造瘘口,对未来生活感到担忧。问:列举此病人腹壁造瘘口护理要点。
男性病人,20岁,破伤风病人,抽搐频繁,引起肘关节脱臼,有窒息可能,呼吸道分泌物较多,此时首选处理是
法院领导在本院初任法官任职仪式上,就落实法官职业道德准则中的“文明司法”和践行执法为民理念的“理性文明执法”提出要求。下列哪些选项属于“文明执法”范围?
关于疏散楼梯,下列技术措施中,哪一项是错误的?[1999年第118题]
票据丧失后可以采取挂失止付、公示催告、普通诉讼等形式进行补救。( )
社会工作研究和其他研究的最大不同是()。
企业集团的基本特征有()。
在宏观上,教与学过程是一个系统过程。下列不属于该系统过程要素的是()
公安执法监督的内容是公安机关及其人民警察在执行职务活动中( )。
李某,男,32岁,某单位汽车司机。李某于2002年8月17日上午11时,同装卸工刘某、王某等三人驾驶解放大卡车由某乡向市里送货(该货车核准载重8吨,该批货物约重13吨)。车超速行驶,当开到某乡政府的十字路口时,将前方同方向骑车的季某连人带车撞出20多米,造
最新回复
(
0
)