问题 探究题

(5分)请你将《探究光照对黄粉虫幼虫生活的影响》的实验过程填写完整。

(1)提出问题:黄粉虫会选择阴暗的环境吗?

(2)作出假设是 :  __________________________________

(3)制定并实施探究方案:在铁盘内放上一层 湿土,一侧盖上不透光的纸板,另一侧盖上透明的玻璃板,在铁盘两侧的中央处各放5只黄粉虫,观察黄粉虫的行为。该实验的变量是        。如果在铁盘两侧中央各放1只黄粉虫是否可以得出准确的结论?       为什么?_______________________________________________.

(4)分析结果,得出结论:该同学对上述实验重复了5次,结果如下表:

 环境 第一次 第二次 第三次 第四次第五次
 明亮  0只  1只  2只  O只  2只
 阴暗  10只  9只  8只  10只  8只
为了使实验结论更准确,应对上述数据做怎样的处理?                         

从中得出的实验结论是       __________________  。

(5)表达和交流。

答案

分析:此题考查的是光对黄粉虫生活的影响的实验,并通过解答此题体会科学探究的方法步骤.解此题的关键是确定、控制变量,设置对照实验.

解答:解:(2)作出假设:应用已有知识,对问题的答案提出可能的设想.作出的假设是:黄粉虫喜欢生活在阴暗的环境.

(3)该实验探究的是“黄粉虫喜欢生活在阴暗的环境中”,实验变量是有无光照,在设计实验时,要给黄粉虫提供明亮和阴暗两种环境.观察黄粉虫对环境的选择,就是形成以光照为惟一变量的对照实验组;不能用1只黄粉虫,如果只用1只黄粉虫做实验,结果具有很大的偶然性(如采集的黄粉虫生病或受处于特殊生长时期等),不足以说明问题.本实验用10只黄粉虫做实验,可以减小误差.当然,采用更多的黄粉虫更好,但会增加实验的难度.

(4)实验材料达一定数量或增加重复次数,计算平均值是为了排除由于偶然性引起的误差.分析实验数据,得出的实验结论:黄粉虫喜欢生活在阴暗的环境中.

故答案为:(2)黄粉虫喜欢生活在阴暗的环境中;(3)光照;(4)不可以;如果只用1只黄粉虫做实验,结果具有很大的偶然性,不足以说明问题;(5)平均值;黄粉虫喜欢生活在阴暗的环境中.

点评:科学探究的一般过程:提出问题、做出假设、制定计划、实施计划、得出结论、表达和交流.探究成功的前提是能够提出有研究价值的问题,并作出符合科学事实的假设;探究成功的关键是制定出恰当的科学探究计划.探究计划包括方法和步骤,以及所需要的材料用具等.

填空题
完形填空

What I noticed first about my new parrot, Chico, was that he couldn’t fly. His wings had been cut short and he was stuck on the   1  just like us humans. When the weather turned nice, I took Chico outside. I sat him on a branch of a tree, hoping to make him   2 . At first he seemed   3 . He walked back and forth on the branch looking anxious or nervous. He didn’t even flap his wings in an attempt to fly. Somehow he knew he was   4 .
One day Chico got especially excited . He paced back and forth and made an incredible amount of   5 . Then all of a sudden he stopped and let out an even louder scream. He started   6  flapping his wings for the first time ever - then he lifted off the   7  like a space shuttle! I was amazed and   8  . Little did I know his feathers had been growing back, and Chico had been   9  until the moment was ripe for escape!
Two days later Chico   10  . First I tried to trick him back with food, but he would not come near me. Then I took his   11  and put it away—still he would not come. Finally, I made him a firm promise that I would let him   12  every day the weather was nice if he did come back.   13  , he flew onto my shoulder.
From that day on, whenever the weather was good I would let him out early and he would fly around and be back before dark. The   14  lasted for two months before suddenly Chico became   15 . The vet said that he had been infected with a disease from the pigeons in the neighborhood. Within a few days he died.
I was very sad. The   16  crossed my mind that if I had not set him free to fly, he would be still alive. But what   17  is there in being a bird if you can’t fly?
Chico made his first break for   18  on a late Monday afternoon in April. When will you make yours? You too can take a   19  when the conditions are right, knowing you too, in your own way, were built to fly. If you don’t    20 , what will be the purpose of your life?
小题1:
A.floorB.earth C.scene D.road
小题2:
A.smarter B.healthier C.happierD.stronger
小题3:
A.disappointedB.determinedC.frightenedD.confused
小题4:
A.incapable B.disabled C.wrongD.stupid
小题5:
A.noise B.progress C.energyD.consideration
小题6:
A.slowly B.gently C.madlyD.gracefully
小题7:
A.ground B.tree C.cage D.branch
小题8:
A.movedB.shocked C.delighted D.excited
小题9:
A.strugglingB.pacing C.flying D.waiting
小题10:
A.left B.returned C.survived D.recovered
小题11:
A.cage B.feather C.chain D.food
小题12:
A.in B.out C.off D.alone
小题13:
A.As usuallyB.At that moment
C.Once in a whileD.At the same time
小题14:
A.action B.attempt C.routine D.effort
小题15:
A.active B.injured C.sad D.ill
小题16:
A.fact B.concern C.thought D.detail
小题17:
A.sense B.mistake C.interest D.problem
小题18:
A.life B.freedom C.fun D.food
小题19:
A.breakB.holiday C.chance D.look
小题20:
A.keep yourself busyB.cheer yourself up
C.let yourself downD.set yourself free