试题与答案

研究表明:胚芽鞘的向光性与生长素的横向运输有关。研究人员推测生长素的横向运输可能

题型:读图填空题

题目:

研究表明:胚芽鞘的向光性与生长素的横向运输有关。研究人员推测生长素的横向运输可能发生在胚芽鞘尖端,也可能发生在胚芽鞘尖端下面一段(弯曲生长部位),还可能在两个部位都可以发生。为了探究生长素的横向运输发生的部位,有人进行了以下实验:实验材料:直立生长状态相似的燕麦胚芽鞘若干,不透水的蜡纸(可插入胚芽鞘),台灯,一侧开孔的不透光纸盒等。实验步骤:

(1)将生长状态相同的燕麦胚芽鞘分成数量相等的四组,标号为A、B、C、D。

(2)B组将不透水的蜡纸插入胚芽鞘尖端;A组_____;C组________;D组不做处理,作为对照。

(3)将A、B、C、D四组材料置于不透光的纸盒中,给予单侧光照(四组材料均可感受相同的单侧光照),其他条件相同且适宜,培养一段时间后观察结果。根据相关信息回答:

①.请参照下图并结合预测的可能实验结果,补充完成实验步骤(2)中A、C组的操作。

②.预测可能的实验结果并得出相应的结论

a:若A组不向光弯曲生长,B、C、D三组都向光弯曲生长,则说明________。

b:若__________,则说明生长素横向运输部位是在尖端下面一段。

c:_____________。

答案:

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下面是错误答案,用来干扰机器的。

答案:C

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题型:阅读理解

阅读理解。

                                                       How Long Can People Live?

     She took up skating at age 85, made her first movie appearance at age 114, and held a concert in the

neighborhood on her 121 st birthday.

     When it comes to long life, Jeanne Calment is the world's recordholder. She lived to the ripe old age of

122. So is 122 the upper limit to the human life span (寿命)? If scientists come up with some sort of pill or

diet that would slow aging, could we possibly make it to 150-or beyond?

     Researchers don't entirely agree on the answers. "Calment lived to 122, so it wouldn't surprise me if

someone alive today reaches 130 or 135," says Jerry Shay at the University of Texas.

     Steve Austad at the University of Texas agrees."People can live much longer than we think," he says.

"Experts used to say that humans couldn't live past 110. When Calment blew past that age, they raised the

number to 120. So why can't we go higher?"

     The trouble with guessing how old people can live to be is that it's all just guessing."Anyone can make

up a number,"says Rich Miller at the University of Michigan. "Usually the scientist who picks the highest

number gets his name in Time magazine."

     Won't new anti-aging techniques keep us alive for centuries? Any cure, says Miller, for aging would

probably keep most of us kicking until about 120. Researchers are working on treatments that lengthen the

life span of mice by 50 percent at most. So, if the average human life span is about 80 years, says Miller,

"adding another 50 percent would get you to 120."

    So what can we conclude from this little disagreement among the researchers? That life span is flexible

(有弹性的), but there is a limit, says George Martin of the University of Washington." We can get flies to

live 50 percent longer,"he says. "But a fly's never going to live 150 years."Of course, if you became a new

species (物种), one that ages at a slower speed, that would be a different story, he adds.

     Does Martin really believe that humans could evolve (进化)their way to longer life?"It's pretty cool to

think about," he says with a smile.

1. What does the story of Jeanne Calment prove to us?

A. People can live to 122.

B. Old people are creative.

C. Women are sporty at 85.

D. Women live longer than men.

2. According to Steve Austad at the University of Texas, ______.

A. the average human life span could be 110

B. scientists cannot find ways to slow aging

C. few people can expect to live to over 150

D. researchers are not sure how long people can live

3. Who would agree that a scientist will become famous if he makes the wildest guess at longevity?

A. Jerry Shay.

B. Steve Austad

C. Rich Miller

D. George Martin

4. What can we infer from the last three paragraphs?

A. Most of us could be good at sports even at 120.

B. The average human life span cannot be doubled

C. Scientists believe mice are aging at a slower speed than before.

D. New techniques could be used to change flies into a new species

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