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. B细节题。根据Every winter
A、Teach their young how to swim. B、Mate and lay eggs. C、Hide from predators. D、Eat different kinds of fish. B细节题。根据Every winter
admin
2017-02-24
58
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 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’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. Now listen to the following recording and answer questions 20 to 22.
20. What do green turtles do when they get to Ascension Island?
21. According to one hypothesis, why do green turtles go to Ascension Island?
22. How is DNA used in research on green turtles?
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
细节题。根据Every winter some green turtles make a 2000km journey from Brazil to Ascension Island in the middle of Atlantic,where they mate and lay eggs.可知,绿乌龟返回阿森松岛是为了交配和产卵。因此,正确答案是B。
转载请注明原文地址:https://kaotiyun.com/show/Y9U7777K
0
大学英语六级
相关试题推荐
A、Thelevelofeducationvariesaroundtheworld.B、Theeconomists’attitudestopopulationdiffergreatly.C、Thelivingstandar
A、Sheisworriedshecan’tattendthecourse.B、Sheisworriedshehastochangeprofessor.C、Sheisworriedshemightnotbeab
A、Whichcountryshouldbeallowedtohavenuclearweapons.B、Thetimefortheirnextcoffeeappointment.C、Whetheritismeaning
A、Anewshuttlebus.B、Ascheduledspaceflight.C、Anairplaneflight.D、Thefirstspaceflight.B根据"spaceshuttle"可以判断是太空飞行,由此可
A、Paintingapicture.B、Hostingaprogram.C、Designingastudio.D、Takingaphotograph.B根据女士所说的“今天我们请布朗教授带着他的新书《时尚映像》来到我们演播厅”,可
A、10.B、4.C、3.D、1.C短文说,Johnson全家用了三年的时间攒够了里程数才换了免费机票。故答案是C。四个选择是数字,初步猜测题目问的可能与数字细节有关,边听边做好笔记。
A、5%.B、10%.C、15%.D、20%.B男士说可以给女士的折扣是10%。故答案是B。从选项可猜测题目与数字细节有关。数字细节题,要边听录音边做好笔记。要注意数字出现时相关联的信息,并留意题目问的问题。听完问题后,可排除没有在对话中提到的A和
A、Smallcompanies.B、Industrialists.C、Tradeunions.D、TheyoungergenerationB细节题。短文提到,工业家们并不反对政府这些计划,他们承认,缩减工作时间会帮助他们减少成本。由此可推
A、Boysaremoreattentivethangirls.B、Girlsaremoreactivethanboys.C、Boysgetmoreattentionthangirls.D、Boysandgirls
A、Boyscryfourtimesasoftenasgirls.B、Girlscryfourtimesasoftenasboys.C、Boyscryasoftenasgirls.D、Girlscryaqu
随机试题
传导舌前2/3味觉的神经是:()
低渗性脱水,血清尚未出现缺钠之前,尿中氯化钠()
成年人,体重60kg,烧伤,于下午4时,送入医院急诊室。检查:意识清,能合作,心率100次/分,血压16.0/11.2kPa(120/84mmHg),面部、胸、腹部、两前臂、两手及两小腿和足部Ⅱ、Ⅲ度烧伤,下午5时开始静脉输液,6时入手术室、清创,晚上8时
修建性详细规划的任务是()。
由不同功能的计划构成的进度计划系统不包括( )。
机电工程中电气设备的主要性能包括()。
依据企业所得税税收优惠政策,下列收入中,属于免税收入的有()。
证券公司成立后,无正当理由超过6个月未开始营业的,或者开业后自行停业连续6个月以上的,由公司登记机关吊销其公司营业执照。()
会议通知要求写明会议的:()
Smokingisconsidereddangeroustothehealth.Ourtobacco-seller,Mr.Johnson,therefore,alwaysaskshis【C1】______,iftheyar
最新回复
(
0
)