首页
登录
职称英语
How sharks navigate the vast and seemingly featureless ocean has long been a
How sharks navigate the vast and seemingly featureless ocean has long been a
游客
2024-01-14
21
管理
问题
How sharks navigate the vast and seemingly featureless ocean has long been a mystery. Now there’s evidence they may follow their noses. Sharks rely on their sense of smell to help chart a path through the ever-shifting waters of the deep seas, according to a new study. Scientists have supposed that the animals navigate by monitoring smell clues or the Earth’s magnetic field, but no one knew for sure.
In new experiments near San Diego, scientists ferried wild leopard sharks about 6 miles (10 kilometers) away from their preferred habitats, fitted them with tracking devices, and stuffed some of the animals’ noses with cotton balls. "Just 30 minutes after being released facing the wrong way, sharks with full use of their smells made a corrective U-turn and then headed straight back to shore, " says study leader Andrew Nosal, a researcher at the Scripps Institution of Oceanography, California.
Sharks with stuffed noses, meanwhile, "appeared lost", wandering aimlessly and swimming more slowly than those that could smell freely. To test sharks’ sense of direction, Nosal and colleagues captured several dozen leopard sharks, a small species found along the coast from Washington State to northern Mexico.
After blocking some of the animals’ noses, the scientists then took the animals on a cruise to deeper waters before slipping them, safe and unharmed, back into the sea. Even the sharks with plugged noses made it partway back to shore before their tracking devices fell off. But those with unplugged noses "took very straight paths" toward home. Nosal supposes the sharks likely sniffed out chemical molecules found in higher and higher doses nearer to land.
Other scientists, however, remain unconvinced. Maybe the animals with plugged noses "were confused by the fact that they had something stuffed in their nose," says Kim Holland, a marine biologist at the University of Hawaii at Manoa. It’s also unlikely the animals were following a smell that grew stronger closer to land, adds Jayne Gardiner, a sensory biologist at the New College of Florida. Animals that couldn’t smell a thing still turned toward the beach, which "suggests something else is really guiding them", she says.
Study leader Nosal responds that sharks with cotton-stuffed nose willingly eat, suggesting that a congested nose doesn’t upset them much. He agrees that sharks use a variety of markers to find their way, "but the point is that smell participates in navigation, " he says, "Our study was only the first step in solving this mystery. " [br] What’s the purpose of writing this passage?
选项
A、To call on people to protect the sharks
B、To present different theories on the mystery of the sharks
C、To let people learn more about the sharks
D、To inform the readers of the findings of a new study on shark
答案
D
解析
根据文中第一段第三句“Sharks rely on their sense of smell to help chart a path through the ever-shifting waters of the deep seas, according to a new study. ”可知,文章主要想要告知读者关于鲨鱼的一项新的研究发现,故选D。
转载请注明原文地址:https://tihaiku.com/zcyy/3360667.html
相关试题推荐
Howsharksnavigatethevastandseeminglyfeaturelessoceanhaslongbeena
Themetabolicrateofsharksislowcomparedwiththeratesofmostotherfishes
A、Theyassistintheorientationprocessbyhelpingthecrabnavigatetowardpos
TheworksofBaudrillardarefilledwithseemingly______buttrulyvacuousrefere
Torpey’sstudyhasturnedaseemingly______topic,thepassport,intoafascinati
Thisnewreportfocusesonhowseemingly(i)______technologicaldesignfeatures,
Recentadvancesindicatethatcuresforsomeseeminglyintractablediseasesare
Thecharlatan’sseeminglyfrankandopendemeanorwasactuallya______meansofe
Late-eighteenth-centuryEnglishculturalauthoritiesseeminglyconcurredthatwo
Late-eighteenth-centuryEnglishculturalauthoritiesseeminglyconcurredthatwo
随机试题
ThemainreasonweexploreMarsistodetermineiflifeeverexistedonthe
BargainbookshoppersmusthavebeenpleasedlookingatAmazon’sbestseller
融合blend
当前,国际金融危机已从局部发展到全球,从发达国家传导到新兴市场国家,从金融领域扩散到实体经济领域,给世界各国经济发展和人民生活带来严重影响。值此关键时刻
Ifyouknowexactlywhatyouwant,thebestroutetoajobistogetspeciali
TheRiseoftheSharingEconomyA)Lastnight40,000peop
某公司系统安全管理员在建立公司的“安全管理体系”时,根据GB/T20269-20
食积兼胆结石,最佳的选择是A.莱菔子B.谷芽C.山楂D.麦芽E.鸡内金
不属于出院患者床单位处理要求的是A.整理病历,交病案室管理 B.撤下病床上床单
事业单位购建工程的建设期间发生非正常中断,则专门借款的利息应计入当期费用。( )
最新回复
(
0
)