托福TPO核心詞匯—A Warm-Blooded Turtle
新托福之TPO閱讀重點(diǎn)單詞語境記憶40
A Warm-Blooded Turtle
When it comes to physiology, the leatherback turtle is, in some ways, more like a reptilian whale than a turtle. It swims farther into the cold of the northern and southern oceans than any other sea turtle, and it deals with the chilly waters in a way unique among reptiles.
A warm-blooded turtle may seem to be a contradiction in terms. Nonetheless, an adult leatherback can maintain a body temperature of between 25 and 26°C (77-79°F) in seawater that is only 8°C (46.4°F). Accomplishing this feat requires adaptations both to generate heat in the turtle’s body and to keep it from escaping into the surrounding waters. Leatherbacks apparently do not generate internal heat the way we do, or the way birds do, as a by-product of cellular metabolism. A leatherback may be able to pick up some body heat by basking at the surface; its dark, almost black body color may help it to absorb solar radiation. However, most of its internal heat comes from the action of its muscles.
Leatherbacks keep their body heat in three different ways. The first, and simplest, is size. The bigger the animal is, the lower its surface-to-volume ratio; for every ounce of body mass, there is proportionately less surface through which heat can escape. An adult leatherback is twice the size of the biggest cheloniid sea turtles and will therefore take longer to cool off. Maintaining a high body temperature through sheer bulk is called gigantothermy. It works for elephants, for whales, and, perhaps, it worked for many of the larger dinosaurs. It apparently works, in a smaller way, for some other sea turtles. Large loggerhead and green turtles can maintain their body temperature at a degree or two above that of the surrounding water, and gigantothermy is probably the way they do it. Muscular activity helps, too, and an actively swimming green turtle may be 7°C (12.6°F) warmer than the waters it swims through.
Gigantothermy, though, would not be enough to keep a leatherback warm in cold northern waters. It is not enough for whales, which supplement it with a thick layer of insulating blubber (fat). Leatherbacks do not have blubber, but they do have a reptilian equivalent: thick, oil-saturated skin, with a layer of fibrous, fatty tissue just beneath it. Insulation protects the leatherback everywhere but on its head and flippers. Because the flippers are comparatively thin and blade-like, they are the one part of the leatherback that is likely to become chilled. There is not much that the turtle can do about this without compromising the aerodynamic shape of the flipper. The problem is that as blood flows through the turtle’s flippers, it risks losing enough heat to lower the animal’s central body temperature when it returns. The solution is to allow the flippers to cool down without drawing heat away from the rest of the turtle’s body. The leatherback accomplishes this by arranging the blood vessels in the base of its flipper into a countercurrent exchange system.
In a countercurrent exchange system, the blood vessels carrying cooled blood from the flippers run close enough to the blood vessels carrying warm blood from the body to pick up some heat from the warmer blood vessels; thus, the heat is transferred from the outgoing to the ingoing vessels before it reaches the flipper itself. This is the same arrangement found in an old-fashioned steam radiator, in which the coiled pipes pass heat back and forth as water courses through them. The leatherback is certainly not the only animal with such an arrangement; gulls have a countercurrent exchange in their legs. That is why a gull can stand on an ice floe without freezing.
All this applies, of course, only to an adult leatherback. Hatchlings are simply too small to conserve body heat, even with insulation and countercurrent exchange systems. We do not know how old, or how large, a leatherback has to be before it can switch from a cold-blooded to a warm-blooded mode of life. Leatherbacks reach their immense size in a much shorter time than it takes other sea turtles to grow. Perhaps their rush to adulthood is driven by a simple need to keep warm.
托福核心單詞
Physiology生理學(xué);生理機(jī)能
原文：When it comes to physiology, the leatherback turtle is, in some ways, more like a reptilian whale than a turtle. 從生理學(xué)上講，棱皮龜在某些方面上更像爬行的鯨魚。
強(qiáng)化記憶： Physiology and anatomy are basic to medical science. 生理學(xué)和解剖學(xué)是醫(yī)學(xué)的基礎(chǔ)。
He bought a book about physiology. 他買了一本生理學(xué)方面的書。
Leatherback棱皮龜
原文：When it comes to physiology, the leatherback turtle is, in some ways, more like a reptilian whale than a turtle. 從生理學(xué)上講，棱皮龜在某些方面上更像爬行的鯨魚。
強(qiáng)化記憶：Leatherback turtles usually mate every other year. 棱皮龜通常是隔年才交配一次。
Scientists have appealed for international cooperation to protect leatherback sea turtles.科學(xué)家呼吁國際性合作來保護(hù)棱皮海龜。
Reptilian爬蟲類動(dòng)物
原文：When it comes to physiology, the leatherback turtle is, in some ways, more like a reptilian whale than a turtle. 從生理學(xué)上講，棱皮龜在某些方面上更像爬行的鯨魚。
強(qiáng)化記憶：The chick is ugly and almost reptilian in its appearance. 這只小雞長得很丑，看起來幾乎像個(gè)爬行動(dòng)物。
The reptilian brain is much like a baby's brain. 爬行動(dòng)物腦有點(diǎn)像嬰兒的大腦。
Chilly寒冷的，可怕的
原文：It deals with the chilly waters in a way unique among reptiles. 它們在應(yīng)對寒冷水域時(shí)有其獨(dú)特的方式。
強(qiáng)化記憶： I was feeling chilly. 我感到冷得難受。
Contradiction矛盾，反駁
原文：A warm-blooded turtle may seem to be a contradiction in terms. 溫血海龜似乎是一個(gè)自相矛盾的術(shù)語。
強(qiáng)化記憶：There is a contradiction between the two sets of figures. 這兩組數(shù)據(jù)相互矛盾。
Your attitude is in contradiction to your character. 你的態(tài)度和你的性格相抵觸。
Radiation輻射，放射物
原文：Its dark, almost black body color may help it to absorb solar radiation. 其深色近乎黑色的體色有助于吸收太陽輻射。
強(qiáng)化記憶： the biological effects of radiation 輻射對生物體的影響
unusually high levels of radiation 超高的輻射強(qiáng)度
Bask曬太陽，取暖，舒適
原文：A leatherback may be able to pick up some body heat by basking at the surface. 棱皮龜可能會通過曬太陽來收集身體所需的熱量。
強(qiáng)化記憶：Turtles like to bask in the sun. 海龜喜歡曝于陽光中。
Each had a private little sun for her soul to bask in. 在她們每一個(gè)人心里，都獨(dú)有一個(gè)小太陽，曬著她們的靈魂。
Proportionate相稱，成比例
原文：For every ounce of body mass, there is proportionately less surface through which heat can escape. 體重每增加一盎司，相應(yīng)的容易流失熱量的表面就越少。
強(qiáng)化記憶：The number of accidents is proportionate to the increased volume of traffic. 交通事故的數(shù)字與交通量的增長成正比。
Wages will rise at a rate proportionate to the amount of work you do. 工資將與你所做的工作量成比例增加。
Loggerhead 紅海龜，笨蛋
原文：Large loggerhead and green turtles can maintain their body temperature at a degree or two above that of the surrounding water, and gigantothermy is probably the way they do it. 紅海龜和綠甲海龜可以維持與周圍水溫略高1攝氏度或2攝氏度或的體溫，可能就是利用的巨溫性。
強(qiáng)化記憶：Mrs Smith enjoys setting people at loggerheads. 史密斯太太喜歡挑撥離間。
Blubber 鯨油，鯨脂
原文：Leatherbacks do not have blubber. 棱皮龜沒有鯨魚那樣的脂肪。
強(qiáng)化記憶：The whale is rich in blubber. 這種鯨油多。
The whale blubber is rendered down to make oil. 鯨的脂肪被煎熬成油。
Equivalent等價(jià)的，相等的
原文：they do have a reptilian equivalent. 它們和爬行類的動(dòng)物有著相似的結(jié)構(gòu)。
強(qiáng)化記憶： Eight kilometers is roughly equivalent to five miles. 八公里約等于五英里。
You will receive the full equivalent of your money. 你將收到與你的款項(xiàng)價(jià)值完全同等的物品。
Flipper鰭
原文：Insulation protects the leatherback everywhere but on its head and flippers. 除了頭部和鰭，這個(gè)“絕緣”結(jié)構(gòu)可以保護(hù)它們的所有部位。
強(qiáng)化記憶：The seal's flipper is homologous with the human arm. 海豹的鰭肢與人類的手臂同源。
It's almost like a flipper action as she kicks down. 她向下踢腿時(shí)有魚鰭的效果。
Blade 刀片，刀鋒
原文：Because the flippers are comparatively thin and blade-like, they are the one part of the leatherback that is likely to become chilled. 因?yàn)槔馄數(shù)啮捪鄬^薄且呈葉片狀，這一部位很有可能會被凍僵。
強(qiáng)化記憶：Blade and handle are the component parts of a knife. 刀身和刀柄是一把刀的組成部分。
The knife's blade gleamed dully in the dark. 刀刃在黑暗中幽幽地閃著光。
Aerodynamic 空氣動(dòng)力學(xué)的
原文：There is not much that the turtle can do about this without compromising the aerodynamic shape of the flipper. 在不損害鰭部氣動(dòng)外形的情況下很少有海龜可以做到這些。
強(qiáng)化記憶：The newspaperman summarized the crux of the aerodynamic phenomenon. 記者總結(jié)了空氣動(dòng)力現(xiàn)象之謎。
These effects appear to be negligible with respect to aerodynamic coefficients. 就空氣動(dòng)力系數(shù)這方面來說，這些影響似乎可以略去。
Countercurrent 逆流，相反
原文：The leatherback accomplishes this by arranging the blood vessels in the base of its flipper into a countercurrent exchange system. 棱皮龜通過鰭下排列的血管流入逆流交換系統(tǒng)來實(shí)現(xiàn)這一點(diǎn)。
強(qiáng)化記憶：Countercurrent washing is applied to reduce acid pollution effectively. 逆流洗滌方式能有效減輕酸污染。
Compromising妥協(xié)的，讓步的
原文：There is not much that the turtle can do about this without compromising the aerodynamic shape of the flipper. 在不損害鰭部氣動(dòng)外形的情況下很少有海龜可以做到這些。
強(qiáng)化記憶：He made the fatal mistake of compromising early. 他犯了過早妥協(xié)的致命錯(cuò)誤。
She turned red and then white in the most compromising fashion. 她的臉始而變紅，繼而轉(zhuǎn)白，一副妥協(xié)的樣子。
Floe 浮冰
原文：That is why a gull can stand on an ice floe without freezing. 這就是為什么海鷗可以站在冰川上而不被凍結(jié)。
強(qiáng)化記憶：Two penguins are standing on ice floe. 兩只企鵝站在一塊浮冰上。
Two Atlantic walruses snuggle on an ice floe near Igloolik, Nunavut, Canada. 加拿大努勒維特伊格盧利克附近，兩頭大西洋海象在浮冰上相互偎依。
Fibrous纖維的
原文：They do have a reptilian equivalent: thick, oil-saturated skin, with a layer of fibrous, fatty tissue just beneath it. 它們和爬行類的動(dòng)物有著相似的結(jié)構(gòu)：厚且含油的皮膚，皮膚下有一層纖維，而脂肪組織就在這個(gè)纖維層下面。
強(qiáng)化記憶：Wetting of fibrous materials can critically affect many manufacturing processes. 纖維材料的潤濕，會嚴(yán)重影響它的許多加工工藝。
Cellophane is made of long, fibrous molecules. 玻璃紙系由長形纖維分子組成。
Gull海鷗
原文：That is why a gull can stand on an ice floe without freezing. 這就是為什么海鷗可以站在冰川上而不被凍結(jié)。
強(qiáng)化記憶：The gull held the fish in its beak. 海鷗嘴里叼著魚。
A lone sea gull flew across the sky. 一只孤獨(dú)的海鷗在空中飛過。
