72. Biological functions of many plants and animals vary in cycles that are repeated every 24 hours. It is tempting to suppose that alteration in the intensity of incident light is the stimulus that controls these daily biological rhythms. But there is much evidence to contradict this hypothesis. Which of the following, if known, is evidence that contradicts the hypothesis stated in the lines above? (A) Human body temperature varies throughout the day, with the maximum occurring in the late afternoon and the minimum in the morning. (B) While some animals, such as the robin, are more active during the day, others, such as mice, show greater activity at night. (C) When people move from one time zone to another, their daily biological rhythms adjust in a matter of days to the periods of sunlight and darkness in the new zone. (D) Certain single-cell plants display daily biological rhythms even when the part of the cell containing the nucleus is removed. (E) Even when exposed to constant light intensity around the clock, some algae display rates of photosynthesis that are much greater during daylight hours than at night. 答案选E，看了解析我也没有弄懂，E选项怎么就反对结论了呢。请NN们给我讲一下，谢谢~~ -- by 会员 上官 (2009/12/27 23:20:33)
题目：动植物的循环是24小时一次的周而复始的。
因此有人说，是不同的光线密度控制动植物的生物节奏的。
问：下面哪一种情况最能反驳上述观点？
A人的体温是随着时间变化而变化的（没有反驳，排除）
B一些动物，白天活跃而另外一些是在晚上活跃（没有反驳，排除）
C人从一个时区走到另一个时区，他们的生理节奏会随着不同时区的白天黑夜长度而改变（这是支持了观点，排除）
D一些单细胞植物表现出每日的节奏。。。（没有反驳，排除）
E如果把海藻放在一个光线不变的环境，一些海藻的光合作用的速度会不一样，白天比晚上的速度快！
这个说明了这种海藻，它的生理节奏是与外界光线不直接相关而是和具体的时间相关，从而反驳了题目中的观点，正确 | 
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发表于 2009-12-27 23:20:33
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