2. 外语
  3. Researchers have noted that ants arrange their dead using the same principles thought to produce the markings on animal s

Researchers have noted that ants arrange their dead using the same principles thought to produce the markings on animal s

admin2011-01-17  49
问题            Researchers have noted that ants arrange their dead using the same
       principles thought to produce the markings on animal skin and on tropical sea
       shells, a first clear example of so-called Turing patterns in higher organisms.
Line    Turing argued that activation occurs through a feedback process that amplifies
(5)     small variations in the concentration of one of the ingredients, while inhibition
       causes a concentration of activity to suppress the appearance of similar
       concentrations nearby. Ant graveyards are an example of a self-amplifying
       activation process: ants are more likely to drop a corpse on a pile than
       elsewhere, and because collecting bodies and adding them to a pile sweeps the
(10)    surrounding space clear, new cemeteries are inhibited from appearing in the
       vicinity of existing ones. While activator-inhibitor mechanisms have previously
       been proposed to explain how predators and prey distribute themselves across an
       ecosystem, it is the first time such a system has conclusively proven that
       Turing’s process operates at the level of colonies and ecosystems.
Of the following descriptions of natural processes, which suggest that the organisms involved depend on the activator-inhibitor mechanism described through Turing’s mathematics? Ⅰ. Pigeons are scattered by a random storm as they make a migration, causing their populations to live in seasonal isolation. Ⅱ. Butterfly populations tend to grow unchecked in certain ecosystems, having few natural enemies. Ⅲ. Lack of food tends to drive many arctic rabbit from the burrows, exposing them to their predators and thereby reducing their population.
选项 A、Ⅰ only
B、Ⅲ only
C、Ⅰ and Ⅱ only
D、Ⅰ and Ⅲ only
E、Ⅰ, Ⅱ, and Ⅲ
答案B
解析
转载请注明原文地址:https://jikaoti.com/ti/UnWYFFFM
本试题收录于： GRE VERBAL题库GRE分类
0

GRE VERBAL

GRE

相关试题推荐
随机试题
最新回复(0)