[請益] TPO13 Biology clock Q5

看板TOEFL_iBT作者 (Erica)時間13年前 (2011/08/31 11:29), 編輯推噓1(104)
留言5則, 2人參與, 最新討論串3/3 (看更多)
Paragraph 2:When crayfish are kept continuously in the dark, even for four to five months, their compound eyes continue to adjust on a daily schedule for daytime and nighttime vision. Horseshoe crabs kept in the dark continuously for a year were found to maintain a persistent rhythm of brain activity that similarly adapts their eyes on a daily schedule for bright or for weak light. Like almost all daily cycles of animals deprived of environmental cues, those measured for the horseshoe crabs in these conditions were not exactly 24 hours. Such a rhythm whose period is approximately—but not exactly—a day is called circadian. For different individual horseshoe crabs, the circadian period ranged from 22.2 to 25.5 hours. A particular animal typically maintains its own characteristic cycle duration with great precision for many days. Indeed, stability of the biological clock's period is one of its major features, even when the organism's environment is subjected to considerable changes in factors, such as temperature, that would be expected to affect biological activity strongly. Further evidence for persistent internal rhythms appears when the usual external cycles are shifted—either experimentally or by rapid east-west travel over great distances. Typically, the animal's daily internally generated cycle of activity continues without change. As a result, its activities are shifted relative to the external cycle of the new environment. The disorienting effects of this mismatch between external time cues and internal schedules may persist, like our jet lag, for several days or weeks until certain cues such as the daylight/darkness cycle reset the organism's clock to synchronize with the daily rhythm of the new environment. 7. According to paragraph 2, what will an animal experience when its internal rhythms no longer correspond with the daily cycle of the environment? A. Disorientation B. Change in period of the internal rhythms C. Reversal of day and night activities Increased D. Sensitivity to environmental factors 答案是A,但我選B。 我不懂A與B的差異,兩個意思都是「受到干擾」,但為何是選A呢? 謝謝解答:) -- -- ※ 發信站: 批踢踢實業坊(ptt.cc) ◆ From: 140.119.41.157

08/31 17:00, , 1F
B要有"certain cues"(日夜循環)生物才會自我調適,否則的話
08/31 17:00, 1F

08/31 17:01, , 2F
internal rhythms不會改變(這段前面有提到)
08/31 17:01, 2F

08/31 17:04, , 3F
那些蝦蟹沒有因為整月整年都黑的而改變 internal rhythms
08/31 17:04, 3F

08/31 17:09, , 4F
補: A是指錯亂的"狀態" B是生物對這狀態的"反應"
08/31 17:09, 4F

09/02 11:37, , 5F
Thank you!!!
09/02 11:37, 5F
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