首页
登录
职称英语
In 1751, Swedish botanist Carolus Linnaeus came up with the novel idea of us
In 1751, Swedish botanist Carolus Linnaeus came up with the novel idea of us
游客
2023-12-03
18
管理
问题
In 1751, Swedish botanist Carolus Linnaeus came up with the novel idea of using flowers as clocks. Morning glories open their trumpet-like petals around 10 a. m. , water lilies at 11 and so on through evening primroses and moonflowers. A full array of these blossoms, planted in a circle, could indicate the time. It was a whimsical notion. But some 250 years later, scientists are seriously interested in the timekeeping mechanisms of nature. "They’re so ubiquitous, they’re almost a signature of life," says molecular neuroscientist Russell Foster of Imperil College, London.
From cockroaches to humans, Foster explores these internal clocks in a fascinating new book, Rhythm of Life, co-authored with British science writer Leon Kreitzman. The author show how the daily patterns known as circadian rhythms influence far more than our sleep. Heart attacks are more common in the morning. Women tend to go to labor in the evening. Severe asthma prevail at night. Although we may jet across time zones, circadian rhythms rule. The book traces the century-long quest to unravel their mechanisms, with some starting outcomes—including the recent discovery that certain genes switch on and off in 24 hour cycles. Even our responses to medicines may depend on when we take them.
Nature has devised internal clocks for a simple reason: they aid survival. "The early bird really does get the work,"—thanks to a silent wake-up call before dawn. A mimosa plant spreads its fernlike leaves during the day to create the maximum surface area for photosynthesis, then folds them up at night to reduce water-vapor loss. It’s not a mere response to light. "They do this even when kept in the dark," says biologist Eugene Maurakis of the Science Museum of Virginia.
In humans, the master clock is a tiny clump of cells in the brain called the suprachiasmatic nuclei. The clocks is reset daily by signals from a novel type of photoreceptor in the eye that Foster discovered. "The blind rely on it, too, provided their eyes haven’t been removed," he says. The result is an orchestrated series of biological events that unfolds in sequence. In the hours before breakfast, the body releases digestive enzymes gradually to be ready for the first meal. Temperature and blood pressure rise in preparation for the day’s demands. This helps explain the morning increase in the heart attacks. Cells reproduce at set times. Hormones rise and fall—many of them according to a predetermined schedule.
The implications for medicine are profound. By timing treatments to complement daily changes in biochemistry, the authors argues, we can boost efficacy and reduce side effects. In one seminal trial, medical oncologist William Hrushesky of the Dorn V. A. Medical Center in Columbia, S. C. , found that by simply reversing the times when he administered two chemotherapeutic drugs, he could extend survival in women with advanced ovarian cancer from 11 percent at five years to 44 Chronobiology International, more than a dozen ailments can currently benefit from carefully timed treatments. In one recent study, he notes, something as simple as low-dose aspirin at bedtime reduced the rate of preterm deliver in pregnant women at risk for hypertension from 14 percent to zero. Aspirin in the morning had little effect. Surprised? Not to Foster and Kreitzman. As they show, timing is everything. [br] What does the word "ubiquitous" in the first paragraph suggest?
选项
A、All kinds of flowers can indicate the time.
B、The timekeeping mechanisms are unique to flowers.
C、Every living thing in nature has got the timekeeping mechanisms.
D、The idea of using flowers as clocks has been widely acknowledged.
答案
C
解析
推断题。首段倒数第一句指出,它们无处不在,几乎成为生命的鲜明特色。这里的“它们”指代前文提到的大自然的计时功能,因此答案为[C]。[A]在前文中出现过,但与题干无关;[B]与原文意思相反,故排除;[D]在原文中没有提及,故排除。
转载请注明原文地址:https://tihaiku.com/zcyy/3241075.html
相关试题推荐
In1751,SwedishbotanistCarolusLinnaeuscameupwiththenovelideaofus
In1751,SwedishbotanistCarolusLinnaeuscameupwiththenovelideaofus
In1751,SwedishbotanistCarolusLinnaeuscameupwiththenovelideaofus
In1751,SwedishbotanistCarolusLinnaeuscameupwiththenovelideaofus
In1751,SwedishbotanistCarolusLinnaeuscameupwiththenovelideaofus
In1751,SwedishbotanistCarolusLinnaeuscameupwiththenovelideaofus
In1751,SwedishbotanistCarolusLinnaeuscameupwiththenovelideaofus
In1751,SwedishbotanistCarolusLinnaeuscameupwiththenovelideaofus
In1751,SwedishbotanistCarolusLinnaeuscameupwiththenovelideaofus
In1751,SwedishbotanistCarolusLinnaeuscameupwiththenovelideaofus
随机试题
In1932,______thedepression,theAmericanpeoplechoseFranklinD.Roosevelt
Janeishappyandexcited.Sheisgoingtobemarriedtomorrowanditisone
Skeletalremainswithanimalbonebladestiedtothefeettestifytoskating’
促进体液免疫的细胞因子是A.IL-2、IFNγ B.IL-1、IL-4 C.
沥青混合料施工摊铺时温度宜在摊铺机的一侧拨料器前方的混合料堆上测试()
公司可以设立分公司,分公司具有法人资格。()
教育目的的性质和方向是由()决定的。 A.科技发展B.社会生产力 C.政
资本资产定价模型是估计权益成本的一种方法。下列关于资本资产定价模型参数估计的说法
下列有关与专家达成一致意见的说法中,错误的是()。A.当就专家工作的性质、范围
根据《公路工程技术标准》,下列公路隧道中,属于长隧道的是()。A.长485m
最新回复
(
0
)