首页
登录
职称英语
[originaltext] If you have ever wondered how an elephant smells, scientists
[originaltext] If you have ever wondered how an elephant smells, scientists
游客
2024-04-18
52
管理
问题
If you have ever wondered how an elephant smells, scientists have the answer. Pretty good. Researchers have discovered that African elephants have the largest number of DNAs dedicated to smell of any mammal. Given the size of their trunks, and how important it is to their survival, it is probably unsurprising that an elephant’s nose is not only the longest in the animal kingdom, but also the most effective. In comparison, humans and other animals have a poor sense of smell. (16) The sense of smell is critical to all mammals, and they use it for sniffing out food, avoiding being killed by other animals, finding mates and locating their offspring. (17-1) In a study published in Genome Research, scientists examined the 13 mammal species and found that African elephants have twice the number of smell DNAs as dogs and five times more than humans. They have around 2,000 DNAs alone that are dedicated to scent. Humans in comparison have just under 400 and other animals, even less. The study found that 20,000 DNAs are responsible for the sense of smell in mammals, of which around half are functional, but the collections differ from each species. (17-2) Horses have around 1,000 smell DNAs, rabbits around 750 and rats about 1,200. (18) And previous studies have revealed that, African elephants can reportedly distinguish between two Kenyan ethnic groups—the Maasai, whose young men demonstrate their manpower by spearing elephants, and the Kamba, who are agricultural people that pose little threat to elephants—through smell.
16. Why is the sense of smell important for mammals?
17. Which of the following mammals has the largest number of smell DNAs?
18. What benefit can African elephants get by telling the difference between the two ethnic groups?
选项
A、Horses.
B、Rats.
C、Dogs.
D、Rabbits.
答案
B
解析
转载请注明原文地址:https://tihaiku.com/zcyy/3561238.html
相关试题推荐
[originaltext]Theround-the-clockavailabilitythatcellphonehavebrought
[originaltext]Imaginethis:youwakeupeachmorningtofindyoursisterly
[originaltext]Imaginethis:youwakeupeachmorningtofindyoursisterly
[originaltext]Imaginethis:youwakeupeachmorningtofindyoursisterly
[originaltext]M:Howisyourtermpapercomingalong?W:Ihavejustfinishedt
[originaltext]M:Howisyourtermpapercomingalong?W:Ihavejustfinishedt
[originaltext]W:Ican’tbelieveKarenislateforsuchanimportantoccasiona
[originaltext]W:Ican’tbelieveKarenislateforsuchanimportantoccasiona
[originaltext]W:Ican’tbelieveKarenislateforsuchanimportantoccasiona
[originaltext]W:Ican’tbelieveKarenislateforsuchanimportantoccasiona
随机试题
ChooseFOURanswersfromtheboxandwritethecorrectletter,A-G,nexttoques
急性胰腺炎时,参与胰腺组织损伤的炎性介质是()。A.血小板活化因子 B.血
确诊肾病综合征大量蛋白尿的标准是A.≥50mg/(kg·d) B.≥250mg
A.疼痛-进餐缓解、空腹及夜间疼痛 B.疼痛-进食疼痛,无间歇,无规律 C.
适时发现可能预示即将发生流动性风险的预警信号,有助于商业银行及时采取措施降低流动
商业银行实施有条件授信时应遵循“先落实条件,后实施授信”的原则,授信条件未落实或
五岁患儿,发热、头痛、呕吐1天,抽搐3次。查体:T39℃,P98次/min,R3
案例九: 下面是某求助者的MMPI测验结果: {图} 社会支持评
纳税人与其关联企业未按照独立企业之间的业务往来支付价款的,税务机关自该业务往来发
A.(3.8~4.6)×10/L B.(1.0~3.0)×10/L C.(1
最新回复
(
0
)