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
2024-04-04
0
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/3539789.html
相关试题推荐
[originaltext]Hello,everyone.Ifeelhappytobehere.Thereisanoldsay
[originaltext]Hello,everyone.Ifeelhappytobehere.Thereisanoldsay
[originaltext]Hello,everyone.Ifeelhappytobehere.Thereisanoldsay
[originaltext]Hello,everyone.Nicetomeetyouhere.Ifyouwanttobuild
[originaltext]Hello,everyone.Nicetomeetyouhere.Ifyouwanttobuild
[originaltext]Moderator:Hello,ladiesandgentlemen.Itgivesmegreatple
[originaltext]If(13)NewZealandbusinessmanGarethMorganhashisdruthers,
[originaltext]AnewstudybytheNationalResearchCouncilandtheInstitut
[originaltext]AnewstudybytheNationalResearchCouncilandtheInstitut
[originaltext]AnewstudybytheNationalResearchCouncilandtheInstitut
随机试题
Googlerecentlyintroducedanewservicethataddssocial-networkingfeature
[originaltext]M:Look,I’mHorrytobotheryouaboutthis,butthatmusic’srea
试讲题目Whatarepeter’shobbies?
钢结构吊车梁和吊车桁架不应下挠。()
下列哪一项不是机械通气治疗的适应证()A.术后恢复期病人 B.心肺复苏后
()地面造价低、施工方便、使用耐久,但如果施工操作不当,易起灰、起砂、脱皮。
建筑材料的实际密度是材料的质量与材料在自然状态下的体积之比。( )
一单层单跨有吊车厂房,平面如题图所示。采用轻钢屋盖,屋架下弦标高为6.0m。变截
A.急性中毒 B.慢性中毒 C.致癌作用 D.致畸作用 E.致突变作用水
某自来水厂工艺流程:原水→空气分离器→活性氧化铝滤池→清水池→用户,用于去除地下
最新回复
(
0
)