OG11 CR 72请教

上官

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~~

tommy8163

intensity是指强度，原文关键是光强是刺激物，而不是时间，所以答案中找和光强有关的选项，E中的constant 正好和原文的alteration对应

fannybeibei

再问下～
intensity我认为是强度，所以是白天晚上光的强度
而B中，为什么在白天晚上光强不同，不同动物的活动不同是与原文无关呢？
我觉得B，E好像差不多啊。。。。
哪位NN说下啊

zzq1978

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

上官

还是不太明白，可以仔细讲下每个选项吗？

cradlepig

我的理解是: 因为原文中提到的关键词是"alteration in the intensity of incident light is the stimulus that controls these daily biological rhythms", 而E中是when expsed to constant light intensity,等于是对原文结论取非.