精英家教网 > 初中英语 > 题目详情
为研究细胞分裂素的生理作用,研究者将菜豆幼苗制成的插条插入蒸馏水中(图1).对插条的处理方法及结粱见图2.

(1)细胞分裂素足一种植物激素。它是由植物体的特定部位_______,再被运输到作用部位,对生长发育起________作用的__________有机物。
(2)制备插条时除去根系和幼芽的主要目的是________:插条插在蒸馏水中而不是营养液中培养的原因是___________·
(3)从图2中可知,对插条进行的实验处理包括_______________。
(4)在实验I中,对A叶进行实验处理,导致B叶__________.该实验的对照处理是________。
(5)实验、III、IV的结果表明,B叶的生长与A叶的关系是: ___________。
(6)研究者推测“细胞分裂素能够引起营养物质向细胞分裂素所在部位运输”。为证明此推侧,用图I所示插条去除B叶后进行实验,实验组应选择的操作最少包括______
(填选项前的符号).
a.用细胞分裂素溶液涂抹A1叶
b.用细胞分裂素溶液涂抹A2叶
c.用14C-淀粉溶液涂抹A1叶
d. 用14C-淀粉溶液涂抹A2叶
e. 用14C-氨基酸溶液涂抹A2叶
f. 用14C-细胞分裂素溶液涂抹A2叶
g. 检测A1叶的放肘性强度
(1) 产生 显著  微量
(2) 除去植物自身体内的细胞分裂素; 防止生长过快,影响实验结果观察
(3) 用细胞分裂素处理不同的叶片。
(4) 生长减缓       A叶和B叶都不进行细胞分裂素处理。
(5) B叶的生长会抑制A叶的生长,甚至使其衰老脱落。
(6) a ,e ,g 解析:
(1)植物激素是由植物自身代谢产生的一类有机物质,并自产生部位移动到作用部位,在极低浓度下就有明显的生理效应的微量物质。
(2)根系和幼芽能产生细胞分裂素;制备插条时除去根系和幼芽的主要目的是除植物自身体内的细胞分裂素;插条插在营养液中,生长过快,影响实验结果观察。
(3) 从图2中可以直接看出,实验的自变量为处理对象之一—叶片。
(4) 不用研究变量处理的为空白对照组。
(5) 实验Ⅱ、Ⅲ、Ⅳ的结果表明,B叶的生长与A叶的关系是:B叶的生长会抑制A叶的生长,甚至使其衰老脱落。
(6) 研究者推测“细胞分裂素能够引起营养物质想细胞分裂素所在部位运输”。为证明此推测,用图1所示插条去除B叶后进行实验,实验组应选择的操作简便,包括a用细胞分裂素溶液涂抹A1叶,e用14C-氨基酸溶液涂抹A2叶,g检测A1叶的放射性强度
考点定位:本题考查植物激素的概念、实验分析能力,属于对识记、应用层次的考查。
练习册系列答案
相关习题

科目:初中英语 来源: 题型:

(10分)据报道:2011年12月31日深圳宝安沙井39岁患者陈某某,被诊断为人感染高致病性禽流感(H5N1)而引发的多脏器衰竭而死亡。禽流感再一次又引起了人们的高度关注。右图是高致病性禽流感病毒H5N1侵入人体后发生免疫反应的图解,图中A、B、C为有关的物质或结构。请据图回答问题:

(1)物质B的化学本质是 ______________。
(2)物质A为____________,是由效应T细胞分泌,又能诱导生成更多的效应_________ 细胞,这是一种____________调节机制。  
(3)效应T细胞与靶细胞密切接触,激活靶细胞内的_____________,并使其通透性、渗透压发生改变,最终___________,释放出病毒与抗体结合,使病毒失去_________________________宿主细胞的能力。
(4)T细胞由__________分化而来,成熟于______________,并随血液和淋巴在体内流动。T细胞在人体免疫应答中除具有图示增殖分化的功能外,还能 ______________。

查看答案和解析>>

科目:初中英语 来源: 题型:

如图,,若,则(  )
A.B.C.D.

查看答案和解析>>

科目:初中英语 来源: 题型:阅读理解

(二)天使(9分)
①小时候,我是一个捣蛋、不爱学习又极爱报复的孩子。无论在家里还是在学校,父母和老师、兄弟和同学都极其厌恶我,然而,在心里我渴望着大家的关爱,就像人们渴望上帝的福泽一样。我一个人独处的时候常常默默祈祷:上帝啊!给我善良、给我宽厚、给我聪明吧,我也想如卡尔列一样成为同学们的榜样。可是,上帝正患耳疾,我的祈祷没有一句应验。我依然是个令人生厌的坏孩子,甚至因为我,没有老师愿意带我们这个班。
②三年级的第一学期,学校里来了一位新老师,她就是年轻的玛利娅小姐。玛利娅小姐刚一站到讲台上,整个班里都沸腾了,她太漂亮啦!我带头吹口哨、飞吻、望空中扔书本,好多男生跟我学,我们的吵闹声几乎要把房顶掀开。
③玛利娅小姐没有像其他老师那样大声叫囔:“安静!安静!”她始终面带微笑地望着我们。奇怪,这样我反而感到无聊,于是我一个手势,大家立即停止了胡闹。玛利娅小姐开始自我介绍,当她转身想把自己的名字写到黑板上时,才发现讲桌上没有粉笔,我注意到她的眉头皱了一下,很快又舒展了。心想,糟了,她肯定识破了我们的把戏。但是,玛利娅小姐却转过身来问:“谁愿意替老师去拿盒粉笔?”刚刚平静下来的沸腾又开始了,怪声怪气的笑声再次淹没了整个教室,好多男生争着去干这件事。
④玛利娅小姐请大家不要争,她会挑一个最合适的人选。玛利娅走下讲台,仔细查看了每一个人,最后她说:“基恩,你去吧。”我说:“为什么是我?”“因为我看得出你热情、机灵又具有号召力,我相信你会把事情做得很好。”
⑤我热情?我机灵?我具有号召力?我竟然有这么多优点?玛利娅一眼就看出了我的优点!要知道,在此之前从未有人说过哪怕一点点的好处,甚至我自己都认为我是一个被上帝抛弃的孩子。
⑥我很快取回一盒粉笔,因为它就藏在教室后面的草丛里。当我正要把粉笔递给玛利娅小姐时,我发现我的手指缝里存满了污垢,衬衣袖口开了线,裤腿上溅满了泥点,更糟糕的是我五个脚趾全从破了的鞋子里露出了头。我很不好意思,可玛利娅小姐一点也不在意这些,她接粉笔的时候给了我一个天使般的微笑,那微笑是一朵百合花淡雅而美丽。玛利娅就是上帝派来的天使。
⑦从此,我决定做一个上进、体面的人,因为我知道天使正在注视着我。
【小题1】.用简洁的语言概括本文写了一件什么样的事情?(2分)
【小题2】.本文的“我”是一个怎样的人?(2分)
【小题3】.请从修辞手法的角度对下面的一句话作简要赏析。(3分)
她接粉笔的时候给了我一个天使般的微笑,那微笑是一朵百合花——淡雅而美丽。
【小题4】.文中说“玛利娅就是上帝派来的天使”,你觉得玛利娅是天使吗?请说明你的理由。(2分)

查看答案和解析>>

科目:初中英语 来源: 题型:阅读理解

为证明光照和重力两种因素对生长素在植物体内的分布哪个影响更大,某研究性学习小组进行了如下探索:
材料用具:品种、大小相同的泡胀玉米种子若干,空易拉罐四个,沙土,不透光的牛皮纸,剪刀等。
方法步骤:
(1)取四个空易拉罐,分别剪去顶盖,装入湿润沙土并分别标号(甲、乙、丙、丁);在每个易拉罐内植入三颗玉米种子,放在温度适宜的阴暗处培养,待苗长到2  cm左右时备用。
(2)将甲、乙、丙、丁均用不透光的牛皮纸包严(留出幼苗生长的足够空间),放在实验台上,甲、乙直立放置,在乙装置的一侧开直径1 cm左右的小口,在它们的侧面0.5 m处用100 W的白炽灯连续照射;丙、丁水平放置,在丙装置的正对地面处开直径1 cm左右的小口,在它们的下方0.5m处用100 W的白炽灯连续照射(装置如图所示);甲、乙、丙、丁的其他条件相同。
实验现象:两昼夜后,如图所示。甲直立生长;乙向光弯曲生长;丁向上弯曲生长;丙也向上弯曲生长,但与丁相比,弯曲度要小一些。

请根据实验现象分析原因并得出结论:
(1)由甲、乙装置内的玉米苗生长情况可知玉米苗具有:________________特性,
(2)由甲、丁装置内的玉米苗生长情况可知玉米苗具有:________特性,
(3)由乙、丙、丁装置内的玉米苗生长情况可知:__________________。
继续探究:
(4)如果实验开始后使整个实验装置失去重力,乙、丙、两个装置的幼苗生长方向将是:乙________,丙________。

查看答案和解析>>

科目:初中英语 来源: 题型:阅读理解


When you see the girl for the first time, you may think she is a boy. She is very outgoing(外向). Who is she? Wang Meng, the Chinese top skater.
On the evening of February 26th, 2010, Wang Meng first got to the finishing line in 1 minute and 29.213 seconds in the women’s 1000 meters short track speed skating final(短道速滑决赛)at the Vancouer Olympic Winter Games(温哥华冬奥会). After she succeeded in the 500-meter and 3000-meter races, she won her third gold medal this time. With this one China won four gold medals in the women’s short track speed skating. That helped China first win the team gold medal in Winter Olympics history.
Just before the final race Wang Meng caught a bad cold and coughed terribly. With the words of “You can, you can do!” she won at last. She said, “I really feel these three gold medals belong to my team, to China. It was with the help of my team that I won the prize.”
Though Wang Meng is only twenty-four, she has been the most successful Chinese skater. Chinese are proud of her and her team. We hope she will be faster in Sochi Olympics in 2014.
【小题1】China won ________gold medals in the women’s short track speed skating.
A.2B.3C.4D.5
【小题2】It took Wang Meng 1 minutes and 29. 213 seconds to finish the________ short track speed skating final.
A.women’s 1000B.men’s 1000
C.women’s 500D.men’s 500
【小题3】In Wang Meng’s opinion, ________made her win the prize at last.
A.a strong bodyB.a bad cold
C.her team’s helpD.much exercise
【小题4】Which of the following is NOT true according to the passage?
A.Wang Meng is very outgoing like a boy.
B.Wang Meng is the most successful Chinese skater.
C.Chinese people are proud of Wang Meng and her team.
D.China has got the team gold medal twice in Winter Olympics history.

查看答案和解析>>

科目:初中英语 来源: 题型:

Although we’re quite busy with our study , some parents ________give us more pressure .
A.neverB.alsoC.alwaysD.still

查看答案和解析>>

科目:初中英语 来源: 题型:阅读理解


Jane was not a good student. Her head was in the clouds(处于幻想之中) most of the time. She wanted to listen in class, but other things seemed more important: her clothes, her hairstyle, films and television. Many times she tried to work hard at her lessons, but soon she became absent-minded.
One day, her math teacher gave the class an important lesson and told her students that there would be a test the next week. She helped them review all the week. Jane seemed to listen in class, but her mind went away again.
The day of the test arrived. Jane couldn’t answer many of the questions on the exam. Mike, a very hard-working student, sat next to Jane. So Jane decided to copy his. Mike was very angry when he found Jane was copying his answers. He changed all his answers so that they were not right. Before the bell rang, Mike quickly changed his answers back into right ones. After the test, Mike turned to Jane and said, “ All those answers you copied from my paper are wrong.”
【小题1】Jane thought a lot of things EXCEPT ________.
A.her clothesB.her study
C.films and televisionD.her hairstyle
【小题2】The math teacher helped her students review for a week because ________.
A.there would be an English test
B.there would be an important lesson
C.she wanted her students to study hard.
D.she wanted them to pass the math test.
【小题3】Jane couldn’t answer many of the questions on the exam because _______.
A.her mind was not in the study most of the time
B.she was not clever.
C.she always slept in class.
D.she didn’t know how to study
【小题4】Mike was angry when he ________.
A.was changing all his answers
B.failed the math test
C.found Jane was copying
D.found Jane copying the wrong answers
【小题5】Which of the following is right?
A.Jane copied the wrong answers.
B.Mike couldn’t answer the questions
C.Jane sat before Mike.
D.Jane tried her best in the exam.

查看答案和解析>>

科目:初中英语 来源: 题型:

______ more, and you’ll improve your spoken English.
A.SpeakB.SpeaksC.SpeakingD.To speak

查看答案和解析>>

同步练习册答案