热门搜索:如何备考GRE GRE填空 GRE数学机经 GRE模考
Even though physiological and behavioral processes are maximized within relatively narrow ranges of temperatures in amphibians and reptiles, individuals may not maintain activity at the optimum temperatures for performance because of the costs associated with doing so. Alternatively, activity can occur at suboptimal temperatures even when the costs are great. Theoretically, costs of activity at suboptimal temperatures must be balanced by gains of being active. For instance, the leatherback sea turtle will hunt during the time of day in which krill are abundant, even though the water is cooler and thus the turtle`s body temperature requires greater metabolic activity. In general, however, the cost of keeping a suboptimal body temperature, for reptiles and amphibians, is varied and not well understood; they include risk of predation, reduced performance, and reduced foraging success. One reptile that scientists understand better is the desert lizard, which is active during the morning at relatively low body temperatures (usually 33.0 C), inactive during midday when external temperatures are extreme, and active in the evening at body temperatures of 37.0 C. Although the lizards engage in similar behavior (e.g., in morning and afternoon, social displays, movements, and feeding), metabolic rates and water loss are great and sprint speed is lower in the evening when body temperatures are high. Thus, the highest metabolic and performance costs of activity occur in the evening when lizards have high body temperatures. However, males that are active late in the day apparently have a higher mating success resulting from their prolonged social encounters. The costs of activity at temperatures beyond those optimal for performance are offset by the advantages gained by maximizing social interactions that ultimately impact individual fitness.
169395pg
weigan610
哈士奇和鸡阿姨
[阅读&逻辑 ]新版冲分救命题 -11894
Select the sentence that presents a conventional requirement that is rejected by the author of the passage.
[阅读&逻辑 ]精选题 -11861
Which of the following, if true of the cave, most weakens the argument?
[阅读&逻辑 ]精选题 -11860
It can be inferred that the “sediments
[阅读&逻辑 ]精选题 -11859
Which of the following best describes the issue raised by the question in the highlighted portion of the passage?
[阅读&逻辑 ]精选题 -11858
It can be inferred that which of the following is true of the “geologic evidence”?
[阅读&逻辑 ]精选题 -11857
Which of the following elements in the debate over the origin of Varanus is NOT provided in the passage?
[阅读&逻辑 ]精选题 -11856
It can be inferred from the passage that the geographical distribution of the Komodo dragon is
[阅读&逻辑 ]精选题 -11855
Which of the following, if discovered to be true, would most tend to suggest that the “correlation” mentioned in the passage held true for the people of the West Branch site?
[阅读&逻辑 ]精选题 -11854
The final sentence of the passage primarily serves to do which of the following?
[阅读&逻辑 ]精选题 -11853
The passage implies which of the following about beavers?
[阅读&逻辑 ]精选题 -11852
The passage provides support for which of the following statements about beaver dams?
[阅读&逻辑 ]精选题 -11851
According to the passage, which of the following best accounts for the apparent bias in antelope-migration direction?
[阅读&逻辑 ]精选题 -11850
The author of the passage implies that during the
[阅读&逻辑 ]精选题 -11849
According to the passage, which of the following is true of an Eurasia-Africa land bridge during ice ages?
[填空 ]精选题 -11843
The political upheaval caught most people by surprise: despite the ______ warning of some commentators, it had never seemed that imminent.
[填空 ]精选题 -11842
Even if the story now seems a surprisingly innocuous overture to the author’s later, more fully developed narrations, it ____ some of the key traits of those bleaker tales.
[填空 ]精选题 -11841
William Perkins, his ______ speaking style notwithstanding, has long been seen as the moderate face of his political party.
[填空 ]精选题 -11840
Just because, as a photographer, Friedlander (i)____ places that most people consider ugly does not mean that he is out to prove they are beautiful. Instead, his work suggests that the photographer simply cannot ignore so much of the built American landscape but is obligated to (ii)_____ what we pass through day in and day out, regardless of (iii)_____.
[填空 ]精选题 -11839
In the search for truth, the knowledge gained by scientists consists of approximations with varying degrees of certainty. Such (i)_____ truth can be highly (ii)_____, as the rapid and relatively steady progress of medical knowledge well exemplifies.
[填空 ]精选题 -11838
History teaches us that science is not _________ enterprise, indeed, it is quite the opposite, a motley assortment of tools designed to safeguard researchers against their own biases.
微信公众号:greonline
高效冲分,预见你想象的目标分!
1.使用雷哥网GRE的时间?
2.通过何种渠道了解到雷哥网GRE?
3.使用雷哥GRE的用途?(可多选)
4.使用雷哥网GRE曾遇到的问题?(可多选)
5.你对雷哥网GRE的优化建议(可多选)
6.向朋友推荐雷哥网GRE的可能性?
不会
不一定
可能
很可能
一定