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Tiger beetles are such fast runners that they can capture [#permalink]
27 May 2008, 16:57
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Tiger beetles are such fast runners that they can capture virtually any nonflying insect. However, when running toward an insect, the beetles intermittently stop, and then, a moment later, resume their attack. Perhaps they cannot maintain their pace and must pause for a moment's rest; but an alternative hypothesis is that while running tiger beetles are unable to process the resulting rapidly changing visual information, and so quickly go blind and stop.
Which of the following, if discovered in experiments using artificially moved prey insects, would support one of the two hypotheses and undermine the other ?
A) When a prey insect is moved directly toward a beetle that has been chasing it, the beetle immediately turns and runs away without its usual intermittent stopping.
B) In pursuing a moving insect, the beetles usually respond immediately to changes in the insect's direction, and pause equally frequently whether the chase is up or down an incline.
C) The beetles maintain a fixed time interval between pauses, although when an insect that had been stationary begins to flee, the beetle increases its speed after the next pause.
D) If, when the beetle pauses, it has not gained on the suspect while pursuing, the beetle generally ends the pursuit.
E) When an obstacle is suddenly introduced just in front of the running beetles, the beetles stop immediately, but they never respond by running around the barrier.
ps. I've not seen this one posted before, so this must be one of those rare ones that you can only dig up when u go seriously deep into gmatprep. Good luck solving it - I took about 3 minutes (but thankfully got it right).