SECTION 3Directions: Each passage in this group is followed by questions based on its cont
SECTION 3
Directions: Each passage in this group is followed by questions based on its content. After reading a passage, choose the best answer to each question. Answer all questions following a passage on the basis of what is stated or implied in the passage.
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.
The main idea of the passage is that
A.explanations of the process by which higher organisms explain themselves have remained elusive until now
B.self-amplifying activation processes may one day explain most natural processes
C.scientists have discovered the first proof of Turing patterns to higher organism communities
D.explanations of how organisms organize themselves into patterns are no longer so elusive as they once were
E.activation processes are essential to the survival of many ant species