问题 探究题

某生物兴趣小组的同学为研究植物的生命活动,设计了以下实验装置.请据图回答下列问题:

(1)装置A,实验进行一段时间后,用手挤压塑料袋,观察到的实验现象是:澄清的      ,此实验证明了                     ;在实验过程中,塑料袋内壁出现的水珠主要来自植的         ,水分是通过叶片上的   散失的.实验选用黑的塑料袋,是为了避免植物进行   作用而影响实验效果.

(2)装置B,当图甲中试管内的气体充满二分之一左右时,迅速取出试管将带火星的卫生香伸入管口内,结果卫生香猛烈燃烧起来,该实验说明光合作用产生了   ,为探究“进行光合作用的是金鱼藻”,装置B设置了如图乙所示的对照组,该对照组有一处明显错误,请你改正;应去掉图乙中的       

答案

(1)石灰水变浑浊;植物呼吸释放的气体是二氧化碳;蒸腾作用;气孔;光合;(2)氧气;金鱼藻

题目分析:(1)二氧化碳有能使澄清的石灰水变浑浊的特性,呼吸作用的实质是分解有机物,释放能量,放出二氧化碳,图A实验装置是为了验证呼吸作用的产物是二氧化碳,实验现象是能够使澄清的石灰水变浑浊;在实验过程中也能进行微弱的蒸腾作用,植物体内的水分以水蒸气的形式从叶片的气孔散发出来,遇塑料袋壁凝结成水滴,本实验选用黑色塑料袋,是为了遮光,以避免植物因进行光合作用消耗掉二氧化碳而影响实验效果。(2)植物的光合作用是在叶绿体里利用光能把二氧化碳和水合成有机物,释放氧气,同时把光能转变成化学能储存在合成的有机物中的过程,甲中能使带火星的卫生香剧烈燃烧,这是氧气具有助燃的性质,说明光合作用产生了氧气。为探究“进行光合作用的是金鱼藻”,装置B设置了如图乙所示的对照组,实验的唯一变量应是金鱼藻,所以应去掉图乙中的金鱼藻,其他条件都应该相同。故答案为:(1)石灰水变浑浊;植物呼吸释放的气体是二氧化碳;蒸腾作用;气孔;光合;(2)氧气;金鱼藻

单项选择题

When I was looking for a Christmas present for my daughter in a toy store, a nicely dressed little girl, with some money in her little hand, was looking at some beautiful dolls. When she saw a doll she liked, she would ask her father if she had enough money. He usually said yes.
At the same time, a boy, with old and small clothes, was looking at some video games. He, too, had money in his hand, but it looked no more than five dollars. Each time he picked up one of the video games and looked at his father, he shook his head.
The little girl had chosen her doll, a very beautiful one. However, she noticed the boy and his father. She saw the boy give up a video game with disappointment and walk to another corner of the store.
The little girl put her doll back to the shelf and ran over to the video game. After she talked to her father, she paid for the video game and whispered(耳语) to the shop assistant.
So the boy got the video game that he wanted for free—he was told it was a prize from the store. He smiled happily, although he felt it was so incredible. The girl saw all this happen. She smiled, too.
When I walked out of the store to my car, I heard the father ask his daughter why she had done that. I would never forget their short talk. " Daddy, didn’t Grandma want me to buy something that would make me happy"
He said, "Of course, she did. "
"Well, I just did!" With that, the little girl started skipping towards their car happily.

Which of the following is TRUE according to the story

A.The little girl was kind and helpful.
B.The video game was a prize from the store.
C.The writer paid for the video game for the boy.
D.The boy bought the video game himself from the store.

选择题