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
2024-04-02
24
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/3537016.html
相关试题推荐
[originaltext]I’vementionedhowDNAhassolvedmanymysteriesinbiology.And
[originaltext]Nowwe’vebeentalkingabouttherevolutionaryperiodintheUnit
[originaltext]Nowwe’vebeentalkingabouttherevolutionaryperiodintheUnit
[originaltext]Nowwe’vebeentalkingabouttherevolutionaryperiodintheUnit
[originaltext]I’dliketolookatavitalaspectofe-commerce,andthatisthe
[originaltext]I’dliketolookatavitalaspectofe-commerce,andthatisthe
[originaltext]I’dliketolookatavitalaspectofe-commerce,andthatisthe
[originaltext][12]Intoday’spersonalitystakes,nothingismorehighlyvalued
[originaltext]Pianosarenormallyfoundinbuildingforobviousreasons.Howeve
[originaltext]M:Ididn’tseeyouincreativewritingclasstoday.Whathappene
随机试题
TheGlobalEconomyOfallthesciences,onlytwoare
[originaltext]InasmallliboratoryattheMedicalUniversityofSouthCaro
C
领导者在整个决策过程中吸收下属参与制定政策,决策权上下分享,这种领导体制的类型称
注:排名前20名的高校,科研院校有:北京工业大学、电子科技大学、哈尔
A.病变累及骨、关节及肌腱、滑囊、筋膜等周围软组织的一组疾病 B.主要表现为周
各种运输方式内外部的各个方面的构成和联系,就是( )。 A.运输系统
案例六: 下面是某求助者的WAIS-RC的测验结果 对于WAIS
下列各项中不符合可靠性要求的是()。A.甲公司按照合理确定的5%的计提比例
XV级岩石的坚固系数的范围是()。A.10~25 B.20~30 C.
最新回复
(
0
)