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、Teach their young how to swim. B、Mate and lay eggs. C、Hide from predators. D、Eat different kinds of fish. BWhat?do?green?turtl
A、Teach their young how to swim. B、Mate and lay eggs. C、Hide from predators. D、Eat different kinds of fish. BWhat?do?green?turtl
admin
2013-04-25
39
问题
I’ve mentioned how DNA have 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. Every winter some green turtles make a 2000 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, 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 question this explanation on the ground that it would be very unlikely that conditions would allowe 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’ve been genetically isolated long enough to have DNA that was very different from the green turtles that nest else where. But when scientists examine 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 this study was a nice example of the usefulness of DNA analysis to biology.
选项
A、Teach their young how to swim.
B、Mate and lay eggs.
C、Hide from predators.
D、Eat different kinds of fish.
答案
B
解析
What?do?green?turtles?do?when?they?get?to?Ascension?Island?
转载请注明原文地址:https://kaotiyun.com/show/tSyO777K
0
托福(TOEFL)
相关试题推荐
SECTION4Questions31-40Questions31-33Completethetablebelow.WriteNOMORETHANTWOWORDSforeachanswer
【21】Shesaysthatnon-nativespeakerstudentsneedtoanticipateand______inordertogetinvolvedinseminardiscussions.
Theuniversityhasproduceda______toinformstudentsaboutthedifferentaccommodationoptionsavailable.BreconHalls
WhatisthepurposeofJaneandRick’smeetingwiththetutor?
learning/studygroups
Completethesentencesbelow.WriteNOMORETHANTHREEWORDSforeachanswer.Ifyouneedtofindinformationonacertainbook
Whichattitudeisassociatedwiththefollowingpeopleduringtheconversation?ChooseSIXanswersfromtheboxandwritetheco
Whichattitudeisassociatedwiththefollowingpeopleduringtheconversation?ChooseSIXanswersfromtheboxandwritetheco
Thefollowingareessentialrequirementsforwhichjobs?Writethecorrectletter,A,BorC,nexttoQuestions11-15.Essential
Thefollowingareessentialrequirementsforwhichjobs?Writethecorrectletter,A,BorC,nexttoQuestions11-15.Essential
随机试题
下列选项中,不属于组织文化发展趋势的是()
关于民事法律关系,下列说法正确的是()
利巴韦林的化学名为乙胺丁醇的化学名为
患者,女,48岁,体检发现子宫黏膜下肌瘤询问护士该病最常见的临床表现,护士告知
下列修测种类中,不属于基本图修测方案的是()。
某公司(甲方)综合楼工程,地下室1层,地上9层,总建筑面积33000m2,箱形基础,框架剪力墙结构。基坑采用土钉墙支护,于5月份完成了土方作业,并制定了雨期施工方案。计划雨期主要施工部位:基础SBS改性沥青卷材防水工程、基础底板钢筋混凝土工程、地下室1层至
()对企业应当纳税的税种、税目、税率以及纳税时限和处罚等作出了规定。
从前,有两个饥饿的人得到一位长者的恩赐:一个人要了一篓鱼,另一个要了鱼竿,他们就分路了。得到鱼的人原地就用篝火煮了鱼,吃了个精光,不久便饿死了。另一个人则提着鱼竿忍饥挨饿向海边走去,可当他看到大海时,最后一点力气也使完了,他眼巴巴地带着无尽的遗憾撒手人间。
某市A区因经济开发需要,决定征用该区某村的集体土地300亩。因土地补偿问题协商不成,该村有80户村民不服,打算申请行政复议。下列哪一说法是正确的?()
对于逻辑表达式((bl&b2)||in),需要_______个测试用例才能完成条件组合覆盖。
最新回复
(
0
)