母蜥蜴为幼仔创造有压力的成长环境-凯发k8官网

母蜥蜴为幼仔创造有压力的成长环境
文章来源:未知 文章作者:enread 发布时间:2012-04-20 02:43 字体: [ ] 
(单词翻译:双击或拖选)

stressed out 1 moms tend to give their developing 2 short shrift, but the hardship may ultimately be a good thing for the babies once they're born, according to a study published in the journal 3 and biochemical 4. stress changes the way animals 5(分配,指定) energy. during 6 attacks or food shortages, 8 are released that help the body to access stored energy. but for pregnant females there's a potential trade-off. stress hormones could rob precious energy from developing embryos, leading to offspring that aren't as healthy.

a research team led by erik wapstra of the university of tasmania, australia, tested the effects of stress on southern grass skinks, which, unlike many 9, give birth to live young rather than laying eggs.

in the lab, the researchers recreated the 10 of a stressful situation by artificially raising levels of the stress 7 corticosterone(肾上腺酮) in pregnant skins. other skinks had their food 11 limited, recreating the stress of a food shortage. the team then measured the health of the stressed mothers and their 12 offspring, and compared their state to mothers and offspring that weren't under stress.

the study found that stressed moms gave birth to smaller offspring that grew more slowly than those born to low-stress mothers. stressed mothers themselves were found to be in better physical shape after giving birth than non-stressed mothers. that's a signal that when stressors are present, mothers tend to allocate energy to self-preservation first.

despite seemingly getting the short end of the stick, the news wasn't all bad for offspring of stressed mothers. "we found that small offspring had larger fat reserves relative to body size…, which may enhance offspring survival in a stressful post-natal environment," the researchers write. previous studies have also shown that smaller 13 lizards often do better when predator 14 is high or when food availability is low.

it appears that a mother's stress-induced selfishness may actually help to pre-adapt her babies for a stressful world.



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1 p0ex0     
n.蜥蜴,壁虎
参考例句:
  • a chameleon is a kind of lizard.变色龙是一种蜥蜴。
  • the lizard darted out its tongue at the insect.蜥蜴伸出舌头去吃小昆虫。
2 0e62a67414ef42288b74539e591aa30a     
n.晶胚;胚,胚胎( embryo的名词复数 )
参考例句:
  • somatic cells of angiosperms enter a regenerative phase and behave like embryos. 被子植物体细胞进入一个生殖阶段,而且其行为象胚。 来自辞典例句
  • evolution can explain why human embryos look like gilled fishes. 进化论能够解释为什么人类的胚胎看起来象除去了内脏的鱼一样。 来自辞典例句
3 aavyk     
adj.生理学的,生理学上的
参考例句:
  • he bought a physiological book.他买了一本生理学方面的书。
  • every individual has a physiological requirement for each nutrient.每个人对每种营养成分都有一种生理上的需要。
4 efjwz     
n.动物学,生态
参考例句:
  • i would like to brush up my zoology.我想重新温习一下动物学。
  • the library didn't stock zoology textbooks.这家图书馆没有动物学教科书。
5 ilnys     
vt.分配,分派;把…拨给;把…划归
参考例句:
  • you must allocate the money carefully.你们必须谨慎地分配钱。
  • they will allocate fund for housing.他们将拨出经费建房。
6 11vza     
n.捕食其它动物的动物;捕食者
参考例句:
  • the final part of this chapter was devoted to a brief summary of predator species.本章最后部分简要总结了食肉动物。
  • komodo dragon is the largest living lizard and a fearsome predator.科摩多龙是目前存在的最大蜥蜴,它是一种令人恐惧的捕食性动物。
7 uyky3     
n.荷尔蒙,激素,内分泌
参考例句:
  • hormone implants are used as growth boosters.激素植入物被用作生长辅助剂。
  • this hormone interacts closely with other hormones in the body.这种荷尔蒙与体內其他荷尔蒙紧密地相互作用。
8 hormones     
n. 荷尔蒙,激素 名词hormone的复数形式
参考例句:
  • this hormone interacts closely with other hormones in the body. 这种荷尔蒙与体內其他荷尔蒙紧密地相互作用。
  • the adrenals produce a large per cent of a man's sex hormones. 肾上腺分泌人体的大部分性激素。
9 9e3fa64f20794483b9c33d06297dcbfb     
n.蜥蜴( lizard的名词复数 )
参考例句:
  • nothing lives in pompeii except crickets and beetles and lizards. 在庞培城里除了蟋蟀、甲壳虫和蜥蜴外,没有别的生物。 来自辞典例句
  • can lizards reproduce their tails? 蜥蜴的尾巴断了以后能再生吗? 来自辞典例句
10 uafyl     
n.生理学,生理机能
参考例句:
  • he bought a book about physiology.他买了一本生理学方面的书。
  • he was awarded the nobel prize for achievements in physiology.他因生理学方面的建树而被授予诺贝尔奖。
11 44cyq     
n.吸入,纳入;进气口,入口
参考例句:
  • reduce your salt intake.减少盐的摄入量。
  • there was a horrified intake of breath from every child.所有的孩子都害怕地倒抽了一口凉气。
12 anlx8     
adj.最后的,结局的,最终的
参考例句:
  • several schools face eventual closure.几所学校面临最终关闭。
  • both parties expressed optimism about an eventual solution.双方对问题的最终解决都表示乐观。
13 okey2     
n.青少年,少年读物;adj.青少年的,幼稚的
参考例句:
  • for a grown man he acted in a very juvenile manner.身为成年人,他的行为举止显得十分幼稚。
  • juvenile crime is increasing at a terrifying rate.青少年犯罪正在以惊人的速度增长。
14 rodzz     
n.密集,密度,浓度
参考例句:
  • the population density of that country is 685 per square mile.那个国家的人口密度为每平方英里685人。
  • the region has a very high population density.该地区的人口密度很高。
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