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
2023-08-12
71
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、Climate.
B、Instinct.
C、Temperature.
D、Salinity.
答案
B
解析
转载请注明原文地址:http://tihaiku.com/zcyy/2920757.html
相关试题推荐
[originaltext]LawshavebeenwrittentogoverntheuseoftheAmericanNati
[originaltext]LawshavebeenwrittentogoverntheuseoftheAmericanNati
[originaltext]IhadflownfromSanFranciscotoVirginiatoattendaconfer
[originaltext]M:Lookatalltheequipmenthere.Theymustbeusedforsomekin
[originaltext]M:Lookatalltheequipmenthere.Theymustbeusedforsomekin
[originaltext]M:Sally,Iheardfromtheradiothatoverhalftheworld’sseven
[originaltext]M:Sally,Iheardfromtheradiothatoverhalftheworld’sseven
[originaltext]M:Sally,Iheardfromtheradiothatoverhalftheworld’sseven
[originaltext]Manyareasaroundtheworldsufferfromfrequentlossofelec
[originaltext]Manyareasaroundtheworldsufferfromfrequentlossofelec
随机试题
MrDuffyraisedhiseyesfromthepaperandgazedoutofhiswindowonthech
Today,California’spublicschoolsareadisaster.【C1】______bydysfunctiona
Shestayedathomeforaweektolookafterherillchild.ill改成sick
Whilethe1970spoppsychotherapymovementfocusedontheimportanceoflett
与腰椎滑脱有关的叙述,正确的是:()A.腰椎关节间部分有骨的缺损
中国银行体系由()组成。A.中央银行 B.监管机构 C.自律组织 D.
具有益肾健脾,收敛固涩,除湿止带功效的药物是A.桑螵蛸 B.海螵蛸 C.莲子
《中华人民共和国义务教育法》中要求学生应尽的义务有哪些?
银行承兑汇票的承兑银行,应当按照票面金额向出票人收取()的手续费。A:千分之一
构造简单、牢固可靠、测压范围广、使用方便、造价低廉、有足够的精度,可与电测信号配
最新回复
(
0
)