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
2023-08-13
56
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/2923722.html
相关试题推荐
[originaltext]Iwanttothankallofthestudentswhoareheretoday.AndI
[originaltext]Withinthenextfewweeksatwin-enginedJetstreamwilltake
[originaltext]Withinthenextfewweeksatwin-enginedJetstreamwilltake
[originaltext]Ifyouweretovisiteducation,asanalien,andsay"What’s
[originaltext]Ifyouweretovisiteducation,asanalien,andsay"What’s
[originaltext]Ifyouweretovisiteducation,asanalien,andsay"What’s
[originaltext]Theadvantagesanddisadvantagesofalargepopulationhavel
[originaltext]Theadvantagesanddisadvantagesofalargepopulationhavel
[originaltext]M:Hi,Janet,wherewereyouatlunchtime?Iwassavingaseatf
[originaltext]W:I’vebeenreadingaboutanewhealthysnackfood.It’smadefr
随机试题
TypesofExaminationsAnexaminationfallsintoone
Accordingtothespeaker,whatisthedefinitionofseniorcitizens?[br][origi
橡皮电线电缆弯曲性能较好,能够在严寒气候下敷设,适用于水平高差大和垂直敷设的场所
某女童,最近出现光线较暗时视物不清症状,且症状逐渐加重,眼睛干涩、畏光,全身皮肤
妊娠合并心脏病的孕妇最易发生心衰的时间是A.24~28周 B.32~34周
承发包工程中,工作票( )。 A.??必须由设备运维单位签发 B.??必须
员工践行职业道德规范——“纪律”的要求是()。 A.学习岗位规则B.
2008年以来,世界经济增长速度全面放缓。2008年美国前三季度GDP环比分别增
巴塞尔核心原则确定了有效监管体系应遵循的25条原则,其中,银行监管当局必须制定审
课程目标的依据主要有哪些方面?() A.对学生的研究 B.对教师的研究 C
最新回复
(
0
)