首页
登录
职称英语
[originaltext]I’ve mentioned how DNA has solved many mysteries in biology. And
[originaltext]I’ve mentioned how DNA has solved many mysteries in biology. And
游客
2024-04-01
28
管理
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、2,000 m.
B、2,000 km.
C、20,000 m.
D、20,000 km.
答案
B
解析
转载请注明原文地址:https://tihaiku.com/zcyy/3536375.html
相关试题推荐
[originaltext]W:Rockstarsnowfaceanewhazard—voiceabuse.[5]Afterlastw
[originaltext]W:Rockstarsnowfaceanewhazard—voiceabuse.[5]Afterlastw
[originaltext]W:Rockstarsnowfaceanewhazard—voiceabuse.[5]Afterlastw
[originaltext]I’vementionedhowDNAhassolvedmanymysteriesinbiology.And
[originaltext]Nowwe’vebeentalkingabouttherevolutionaryperiodintheUnit
[originaltext]Nowwe’vebeentalkingabouttherevolutionaryperiodintheUnit
[originaltext]Nowwe’vebeentalkingabouttherevolutionaryperiodintheUnit
[originaltext]I’dliketolookatavitalaspectofe-commerce,andthatisthe
[originaltext]I’dliketolookatavitalaspectofe-commerce,andthatisthe
[originaltext][13]Americansaresufferingfromaserioussleepdeficitasthey
随机试题
Animalsarequitedifferentfromhumanbeings______animalshavenoaptitudefo
EvenmanyearlyleadersoftheUnitedStateshaveprovidednamesfortowns,only
Hehadjust【C1】gra______fromHarvardUniversityandwaslivinginManhatta
现场培训的具体形式有()。A.工作指导法 B.个别指导法 C.案例研讨法
电缆隧道在进入建筑物处以及在变电所围墙处,应设带门的防火墙,并应每隔()m安
方程y2=2-x表示的空间曲面为()。A.球面 B.旋转双曲面 C.圆锥面
当高频通道与载波通道混用一相时,高频或通信发生异常或需要()时,合上耦合电
断路器端子箱、机构箱、汇控柜指示灯更换时,应戴(),使用的工具应绝缘良好,防止发
简述建构主义学习观的基本内容。
人在每一瞬间,将心理活动选择了某些对象而忽略了另一些对象。这一特点指的是注意的(
最新回复
(
0
)