DNA是主要的遗传物质是指

DNA是主要的遗传物质是指 遗传物质即亲代与子代之间传递遗传信息的物质。除一部分病毒的遗传物质是RNA外，其余的病毒以及全部具典型细胞结构的生物的遗传物质都是DNA。 2 脱氧核糖核酸 脱氧核糖核酸 大多数生物的遗传物质是DNA，少数生物(如部分病毒)的遗传物质是RNA 生物中有丝分裂中DNA与染色体数量的变化图 2011-9-12 01:29 提问者:斑点狗的一天悬赏分:浏览次数:次 | 10 | 3445 我来帮他解答 2011-9-12 11:28 推荐答案 左边那幅为有丝分裂DNA与染色体数量的变化图。 有丝分裂DNA含量图: a-b:细胞分裂间期染色体复制(实则为DNA的复制和有关蛋白质的合成，而染色体本身的数量不会增加)，所以DNA含量加倍。 b-c:前期到后期有染色体的移动和着丝点的分裂，但对DNA含量无影响。 c-d:细胞分裂成两个细胞，DNA平均分配到两个细胞中，含量减半。 有丝分裂染色体数图: f-g:上个图中已解释过，染色体复制但染色体的数量不会加倍(染色体的数目实则为着丝点的数目)。 g-h:后期着丝点一分为二，所以染色体的数也随之加倍。 i-j:细胞分裂成两个细胞，染色体平均分配到两个细胞中，含量减半。 to West rear, to County Shen Liqun report guerrillas breakout Hou of action situation, boat via Zhejiang wuxing daughter town Shi, six people has a NI surname "spies" (enemy) midway tuogu landing tipsters, away from small town three in Xu, was day Elves Li Taishan Department captured, five people all killed, broken corpse sank Yu River in the. On January 18, 1943, when the Japanese army militiamen arrested 53 people in Wuzhen, transferred to the tomb of the former Japanese military police command (in the "Tai" Jiang Yuan), the 28th in Shenyang North of jade bang massacred them. Hu Maosheng knife wounds woke up in the middle of them, crawling out from the dead, in the tomb of Gao Changhai residents, saved by bing. Such as Hu Maosheng, Gao Changhai is a witness to this tragedy. (B) in memory of "massacre" Xu Youyong yan tomb is the copper law. Copper originally was called Luo yan Tomb, because Eastern Han dynasty distinguished prose poems my father yan Tan bogey was buried in the town's water. Has a long history here, cultural atmosphere, and there are many old houses, and left many people with lofty ideals. Business flourished here, is the hub of four townships of agricultural and sideline products, wine culture has a long history. The outskirts of the town has left, "Huang Chi", originally Yue water hides to West rear, to County Shen Liqun report guerrillas breakout Hou of action situation, boat via Zhejiang wuxing daughter town Shi, six people has a NI surname "spies" (enemy) midway tuogu landing tipsters, away from small town three in Xu, was day Elves Li Taishan Department captured, five people all killed, broken corpse sank Yu River in the. On January 18, 1943, when the Japanese army militiamen arrested 53 people in Wuzhen, transferred to the tomb of the former Japanese military police command (in the "Tai" Jiang Yuan), the 28th in Shenyang North of jade bang massacred them. Hu Maosheng knife wounds woke up in the middle of them, crawling out from the dead, in the tomb of Gao Changhai residents, saved by bing. Such as Hu Maosheng, Gao Changhai is a witness to this tragedy. (B) in memory of "massacre" Xu Youyong yan tomb is the copper law. Copper originally was called Luo yan Tomb, because Eastern Han dynasty distinguished prose poems my father yan Tan bogey was buried in the town's water. Has a long history here, cultural atmosphere, and there are many old houses, and left many people with lofty ideals. Business flourished here, is the hub of four townships of agricultural and sideline products, wine culture has a long history. The outskirts of the town has left, "Huang Chi", originally Yue water hides to West rear, to County Shen Liqun report guerrillas breakout Hou of action situation, boat via Zhejiang wuxing daughter town Shi, six people has a NI surname "spies" (enemy) midway tuogu landing tipsters, away from small town three in Xu, was day Elves Li Taishan Department captured, five people all killed, broken corpse sank Yu River in the. On January 18, 1943, when the Japanese army militiamen arrested 53 people in Wuzhen, transferred to the tomb of the former Japanese military police command (in the "Tai" Jiang Yuan), the 28th in Shenyang North of jade bang massacred them. Hu Maosheng knife wounds woke up in the middle of them, crawling out from the dead, in the tomb of Gao Changhai residents, saved by bing. Such as Hu Maosheng, Gao Changhai is a witness to this tragedy. (B) in memory of "massacre" Xu Youyong yan tomb is the copper law. Copper originally was called Luo yan Tomb, because Eastern Han dynasty distinguished prose poems my father yan Tan bogey was buried in the town's water. Has a long history here, cultural atmosphere, and there are many old houses, and left many people with lofty ideals. Business flourished here, is the hub of four townships of agricultural and sideline products, wine culture has a long history. The outskirts of the town has left, "Huang Chi", originally Yue water hides 考理综实验应对指南 作者:非花菲叶 于 2012-05-07 20:41:36 发表 只看该作者 在这些年的高考理科综合试卷中常有生物实验题出现。有的是设计实验的全过程，有的是修正实验设计的不足。如何才能解答好生物实验设计题呢,这里北京新东方为大家提供一种解题思路。 1.运用科学原理指导实验 解生物实验设计题时，一定要认真审题。在审题中最关键的是要明确实现本实验目的的科学原理。 例如2000年理综实验高考题中“血液中的钙离子在血液凝固过程中起重要作用，缺乏则血液不能凝固。”这就是本实验的根本原理。 遵循这一原理，设法除去血液中的钙离子和添加进去的钙离子，设计实验的方向就不会错。此题中“草酸钾溶液能与血液中的钙离子发生反应，形成草酸钙沉淀，起抗凝作用”。这只是一条除去血液中钙离子的原理，是解决实验中某一问题所需运用的原理，是本实验的辅助原理。 2.遵循实验原则设计实验 要使实验设计得科学，力求无懈可击，在设计实验时必须遵循以下几个原则: (1)设置对照原则 (2)单因子变量原则 (3)平行重复原则 例如:为了证明土壤中的微生物能分解农药，必须将土壤分为两等份，装入两个大小相同的容器，一个高温灭菌，一个不做处理，造成一个容器中的土壤中无生活的微生物，一个容器中的土壤中有生活的微生物。然后进行实验，才能说明问题。这就是设置对照原则。 在进行此实验时，让两个容器中的土壤在一切其他条件都相同的情况下进行实验，惟独不同的只是一个容器中的土壤中有微生物，一个容器中的土壤中无微生物，有无微生物就成了这一实验的单因子变量。这就是单因子变量原则。 在进行此实验时，有些情况的出现是有偶然性的，多做几个对照实验，出现相 to West rear, to County Shen Liqun report guerrillas breakout Hou of action situation, boat via Zhejiang wuxing daughter town Shi, six people has a NI surname "spies" (enemy) midway tuogu landing tipsters, away from small town three in Xu, was day Elves Li Taishan Department captured, five people all killed, broken corpse sank Yu River in the. On January 18, 1943, when the Japanese army militiamen arrested 53 people in Wuzhen, transferred to the tomb of the former Japanese military police command (in the "Tai" Jiang Yuan), the 28th in Shenyang North of jade bang massacred them. Hu Maosheng knife wounds woke up in the middle of them, crawling out from the dead, in the tomb of Gao Changhai residents, saved by bing. Such as Hu Maosheng, Gao Changhai is a witness to this tragedy. (B) in memory of "massacre" Xu Youyong yan tomb is the copper law. Copper originally was called Luo yan Tomb, because Eastern Han dynasty distinguished prose poems my father yan Tan bogey was buried in the town's water. Has a long history here, cultural atmosphere, and there are many old houses, and left many people with lofty ideals. Business flourished here, is the hub of four townships of agricultural and sideline products, wine culture has a long history. The outskirts of the town has left, "Huang Chi", originally Yue water hides 同的结果，更有说服力，更具科学性。让这几组实验装置在相同条件下同时进行， 这就是平行重复原则。 3.准确地运用实验材料支持实验 选用实验材料应讲究，否则将不能支持你的实验结论。 例如想证明微生物的营养要素必须有氮源。我们需做一个对照实验:一个培养 基中加入氮素，一个不含氮素。于是为你提供两种实验材料，一是NH4NO3、一是 人尿。这时你不能认为人尿来的容易，又含有尿素等含氮的有机物，就用人尿作氮 源，因为人尿中还含有无机盐等多种成分，说明不了本实验的结论。 4.选定最优程序进行实验 在明确了实验目的，明确了实验原理，选准实验材料，遵循实验原则后，就应 该编制一个实验程序进行实验。 对编制的实验程序，还要仔细推敲，形成一个最优化的程序，使实验科学、简 捷地进行。 在选定最优程序中有的步骤可同时进行，那就可遵循统筹法，让要等待的步骤 先做，接着穿插下一步实验，以节约时间，同时也尽量减少因时间过长带来的不良 影响。 5.答题时讲究用词科学、准确 有了如上所述的基本素质，最终还要通过完美的回答来展示自己的能力。答题 时关键是用词上讲究科学、准确。 例如“假设牛毛的黑色对棕色是显性，现有一匹黑色公牛，想在一个繁殖季节 中测定出是纯种还是杂合子，请设计检测办法”。如果同学是这样回答“在这一繁 殖季节，让这匹黑色公牛与一匹棕色母牛交配，若生出棕牛，则为杂合子;若只生 出黑牛，则为纯种。”这样回答大方向是正确的，但关键字眼上用词不当，反映学 生思维的不全面或缺乏一些必要的常识。应该改为“让这匹黑色公牛与多匹棕色母 牛交配”。用“多匹”两字，答题的科学性就跃然纸上。因为黑色公牛与多匹棕色 母牛交配，才有较多的机会出现棕牛，牛一般一胎一头，没有一定数量的后代，就 可能出现不了棕牛，从而导致你做出错误的判断。 高考理综生物学实验复习应该注意的几个问题(?) 四川绵阳第一中学 冯永康 编者按:在近年的理科综合能力测试中～实验都是作为重要的考查之一～以突出学习能力和科学素养的考查为目标～其分值比例也是呈现逐年上升的趋势～试题呈现形式愈趋灵活多样。从2006年起～全国的各套理科综合能力测试题～都对“实验与探究能力”的4个层次～作了较为全面的考查。在2011年高考到来之际～我们有幸邀请到四川绵阳第一中学特级教师冯永康老师～就“高考理综生物学实验复习应该注意的问题”与师生进行系列交流和探讨～以期对同学们的应考给予指点和帮助。 1 教科书中高考实验复习的基本方法 1(1 归类复习 《考试大纲》(旧人教版)中“考试范围”所列出的“实验、实习和研究性学习”共to West rear, to County Shen Liqun report guerrillas breakout Hou of action situation, boat via Zhejiang wuxing daughter town Shi, six people has a NI surname "spies" (enemy) midway tuogu landing tipsters, away from small town three in Xu, was day Elves Li Taishan Department captured, five people all killed, broken corpse sank Yu River in the. On January 18, 1943, when the Japanese army militiamen arrested 53 people in Wuzhen, transferred to the tomb of the former Japanese military police command (in the "Tai" Jiang Yuan), the 28th in Shenyang North of jade bang massacred them. Hu Maosheng knife wounds woke up in the middle of them, crawling out from the dead, in the tomb of Gao Changhai residents, saved by bing. Such as Hu Maosheng, Gao Changhai is a witness to this tragedy. (B) in memory of "massacre" Xu Youyong yan tomb is the copper law. Copper originally was called Luo yan Tomb, because Eastern Han dynasty distinguished prose poems my father yan Tan bogey was buried in the town's water. Has a long history here, cultural atmosphere, and there are many old houses, and left many people with lofty ideals. Business flourished here, is the hub of four townships of agricultural and sideline products, wine culture has a long history. The outskirts of the town has left, "Huang Chi", originally Yue water hides 有17项，对这17个实验，都要做到以实验图为主线，? 突出实验原理的理解和应用;? 熟悉实验要用到的器材的选择、作用和使用方法;? 明确实验设计的基本思路和实验步骤的程序;? 清楚实验数据的测量、数据的处理方法;? 强化对实验现象的观察分析、实验结论的归纳总结等。 实验类型 考纲知识要点 (1)生物组织中还原糖、脂肪、蛋白质的生物组织有机成分的 鉴定 (2)叶绿体中色素的提取和分离 提取、分离和鉴定 验证(3)DNA的粗提取与鉴定 性 (4)高倍显微镜的使用和观察叶绿体 实验 (5)细胞质流动的观察 显微镜下的观察 (6)观察植物细胞的有丝分裂 (7)观察植物细胞的质壁分离与复原 (8)比较过氧化氢酶和Fe3+的催化效率 酶的催化特点 (9)探索淀粉酶对淀粉和蔗糖的作用 (10)温度对酶活性的影响 (11)植物向性运动的实验设计和观察 (12)设计实验，观察生长素或生长素类 探究似物对植物生长发育的影响 性 设计与观察 (13)设计并制作小生态瓶，观察生态系 实验 统的稳定性 (14)观察SO2对植物的影响 (15)调查人群中的遗传病 调 查 (16)种群密度的取样调查 (17)调查环境污染对生物的影响 1(2 使用高倍显微镜必须注意几个原则 使用显微镜观察的实验内容复习中，除了熟悉显微镜的基本结to West rear, to County Shen Liqun report guerrillas breakout Hou of action situation, boat via Zhejiang wuxing daughter town Shi, six people has a NI surname "spies" (enemy) midway tuogu landing tipsters, away from small town three in Xu, was day Elves Li Taishan Department captured, five people all killed, broken corpse sank Yu River in the. On January 18, 1943, when the Japanese army militiamen arrested 53 people in Wuzhen, transferred to the tomb of the former Japanese military police command (in the "Tai" Jiang Yuan), the 28th in Shenyang North of jade bang massacred them. Hu Maosheng knife wounds woke up in the middle of them, crawling out from the dead, in the tomb of Gao Changhai residents, saved by bing. Such as Hu Maosheng, Gao Changhai is a witness to this tragedy. (B) in memory of "massacre" Xu Youyong yan tomb is the copper law. Copper originally was called Luo yan Tomb, because Eastern Han dynasty distinguished prose poems my father yan Tan bogey was buried in the town's water. Has a long history here, cultural atmosphere, and there are many old houses, and left many people with lofty ideals. Business flourished here, is the hub of four townships of agricultural and sideline products, wine culture has a long history. The outskirts of the town has left, "Huang Chi", originally Yue water hides 构和使用方法外，需要着重把握好以下几个原则: ? 用眼原则:左眼注视目镜，右眼睁开。这样，一可减轻左眼疲劳，二方便绘图。 ? 物镜选用原则:先低倍后高倍，由低倍到高倍，可以用低倍物镜观察清楚的就勿需使用高倍物镜。 ? 准焦螺旋使用原则:先粗后细，由粗到细。 此外，目镜和物镜选用的差异、反光镜和光圈的选用、装片移动方向的确定、显微镜下视野中污物的判定，等等，都是应该引起注意的。 1(3 实验材料的选择和试剂的配制 (1)还原糖的鉴定:要选择含还原糖量较高、颜色较浅的材料，这样颜色反应才明显。通过实验比较，颜色反应的明显程度依次为苹果、梨、白色甘蓝叶、白萝卜。 (2)脂肪的鉴定:要选择富含脂肪的材料，如花生、蓖麻等，提前浸泡3,4 h。如果是新花生种子，可以不必浸泡，否则切下的薄片不易成形。 )蛋白质的鉴定:最好的实验材料是鸡蛋清，其蛋白质含量相对高，配制的提取(3 液透明，与双缩脲试剂反应后，颜色反应明显，但蛋清液需要稀释。 (4)在观察叶绿体时，宜选用叶绿体大、数目少的材料。如阴生植物藓类的叶、菠菜叶的下表皮(稍带叶肉)等。由于在不同的光照下，叶绿体可以运动并改变在细胞中的分布位置。所以，在不同光照下采集的材料，其叶内叶绿体的形态有所不同。 (5)在观察细胞质的流动时，要选用细胞质流动较快的植物，如黑藻的幼嫩叶片、南瓜幼苗的表皮毛、小麦的根毛、向日葵舌状花瓣的表皮或大白菜内层叶片叶脉的表皮细胞等。选取实验材料时，最好将所要取材的植物体置于温暖的阳光下照射1,2小时，以使植物细胞处于旺盛的生活状态。 (6)在植物细胞的质壁分离和复原的实验时，要选择生活的、成熟的(具有大液泡)、有颜色的(如紫色洋葱)植物细胞;没有大液泡的植物细胞则质壁分离现象不明显。死的植物细胞中的细胞膜，由于失去了选择透过性，所以不能发生质壁分离。 (7)在有关酶的催化特点的探究实验中，常选用动物新鲜肝脏做实验材料，原因是细胞内的过氧化氢酶未被破坏，从而提高实验现象的对比程度。也可选用植物的组织(如to West rear, to County Shen Liqun report guerrillas breakout Hou of action situation, boat via Zhejiang wuxing daughter town Shi, six people has a NI surname "spies" (enemy) midway tuogu landing tipsters, away from small town three in Xu, was day Elves Li Taishan Department captured, five people all killed, broken corpse sank Yu River in the. On January 18, 1943, when the Japanese army militiamen arrested 53 people in Wuzhen, transferred to the tomb of the former Japanese military police command (in the "Tai" Jiang Yuan), the 28th in Shenyang North of jade bang massacred them. Hu Maosheng knife wounds woke up in the middle of them, crawling out from the dead, in the tomb of Gao Changhai residents, saved by bing. Such as Hu Maosheng, Gao Changhai is a witness to this tragedy. (B) in memory of "massacre" Xu Youyong yan tomb is the copper law. Copper originally was called Luo yan Tomb, because Eastern Han dynasty distinguished prose poems my father yan Tan bogey was buried in the town's water. Has a long history here, cultural atmosphere, and there are many old houses, and left many people with lofty ideals. Business flourished here, is the hub of four townships of agricultural and sideline products, wine culture has a long history. The outskirts of the town has left, "Huang Chi", originally Yue water hides 马铃薯的块茎、萝卜的肉质根等)做实验材料。因为过氧化氢酶比较广泛地存在于动植物组织细胞中。 (8)正确配制和使用斐林试剂与双缩脲试剂:配制这两种试剂时，都要用到NaOH溶液和CuSO4溶液，但配制时，溶液浓度不同，使用原理和方法也有明显区别。(见下表) 斐林试剂 双缩脲试剂 配甲(A)液 0(1 g/mLNaOH 0(1 g /mLNaOH 方 乙(B)液 0(05 g/mLCuSO 0(01 g/mL CuSO 44 甲、乙液混合均匀，现配使用方法 先A液后B液，不能混用 现用 双缩脲试剂中起作用的是碱2+斐林试剂中起实质作用的是(与蛋白质结合性环境中Cu2-生成的Cu(OH)络离子，放形成紫色络合物)，因而必须反应原理 4 置过长就会形成Cu(OH)沉淀先后使用。使用CuSO时，溶24及注意事项 或CuCO沉淀，因而无法反液不能过量，否则蓝色的3 应。 CuSO溶液将遮蔽显色反应4 中产生的紫色。 此外，在尿糖的鉴定等临床研究或检测中，常选用班氏试剂(Benedict试剂)，因为班氏试剂较之斐林试剂，要稳定一些，测定的效果也要灵敏一些。【未完待续】 高考理综生物学实验复习应该注意的几个问题(?) 四川绵阳第一中学 冯永康 在高考理综生物学实验的复习中，通过教科书中17个实验的系统复习，不仅要做到以实验流程图为主线，? 突出实验原理的理解和应用;? 熟悉实验要用到的器材的选择、作用和使用方法;? 明确实验设计的基本思路和实验步骤的程序;? 清楚实验数据的测量、数据的处理方法;? 强化对实验现象的观察分析、实验结论的归纳总结等以外，还要求考生:对教科书中的实验原理、实验方法以及实验技术，能够做到“移花接木”和迁移运用，也就是说要学会进行简单的实验的设计与评价。 2(实验方案的设计与评价 实验方案的设计着重考查考生:确定实验原理，选择实验器材，安排实验步骤，设计实验数据的处理方法和分析实验现象，得出正确的实验结论，以及对提供的一些实验方案 进行补充、完善和评价等。 在实验方案的设计与评价中，必须高度关注以下几个方面: to West rear, to County Shen Liqun report guerrillas breakout Hou of action situation, boat via Zhejiang wuxing daughter town Shi, six people has a NI surname "spies" (enemy) midway tuogu landing tipsters, away from small town three in Xu, was day Elves Li Taishan Department captured, five people all killed, broken corpse sank Yu River in the. On January 18, 1943, when the Japanese army militiamen arrested 53 people in Wuzhen, transferred to the tomb of the former Japanese military police command (in the "Tai" Jiang Yuan), the 28th in Shenyang North of jade bang massacred them. Hu Maosheng knife wounds woke up in the middle of them, crawling out from the dead, in the tomb of Gao Changhai residents, saved by bing. Such as Hu Maosheng, Gao Changhai is a witness to this tragedy. (B) in memory of "massacre" Xu Youyong yan tomb is the copper law. Copper originally was called Luo yan Tomb, because Eastern Han dynasty distinguished prose poems my father yan Tan bogey was buried in the town's water. Has a long history here, cultural atmosphere, and there are many old houses, and left many people with lofty ideals. Business flourished here, is the hub of four townships of agricultural and sideline products, wine culture has a long history. The outskirts of the town has left, "Huang Chi", originally Yue water hides 2(1 实验必须遵循的三大基本原则: (1)设置对照原则:在实验设计中，为排除无关条件的干扰，常常要设立对照实验。通过干预或控制研究对象，以消除或减少实验误差，鉴别实验中的处理因素与非处理因素的差异。常见对照方法主要有: ? 空白对照 不给对照组任何处理因素。如:在研究甲状腺激素促进蝌蚪发育实验中，先取等量的同龄且发育状态相同的小蝌蚪60只，分为两组放入容积相同的两个玻璃缸，加入等量的自然水和蝌蚪饲料;一组加入甲状腺激素，另一组不加任何药品，就是空白对照。 ? 条件对照 给对照组施以部分实验因素，但不是所要研究的实验因素。如:在上述空白对照的举例中，如果取等量的同龄且发育状态相同的小蝌蚪60只，分为三组(编号甲、乙、丙)放入容积相同的三个玻璃缸，加入等量的自然清水和蝌蚪饲料;甲组加入甲状腺激素，乙组加入甲硫咪唑(甲状腺抑制剂)，是条件对照，丙组不加任何药品，是空白对照。 ?相互对照 不单设对照组，而是几个实验组相互对照。例如:验证植物根对矿质离子有选择吸收的特性，可把蕃茄和水稻分别培养在成分相同的培养液中，过一段时间后，测定培养液中各种矿质元素离子浓度的变化，就会发现蕃茄吸收Ca多，吸收Si少;而水稻吸收Si多，吸收Ca少。以上就是两个实验组的相互对照。 ?自身对照 对照和实验都在同一研究对象上进行。如:要研究植物根具有向重力性，茎具有背重力性，可把某一植株横放于培养基上，让其自然生长，经过一段时间后，便可观察到根向重力生长，茎背重力生长。这里，对照和实验都在同一个体上进行，属于自身对照。 (2)单一变量原则:控制其它因素不变，只改变其中一个因素，观察其对实验结果的影响。如探索温度对酶活性的影响时，只能改变反应的温度，其它如pH、酶浓度等因素就要完全相同且适宜。 (3)平行重复原则:对所做的实验在同样条件下，进行足够次数的重复，不能只进行1,2次便轻易得出结论。需要选择的实验材料的样本数(如植株的数目、种子的粒数、实验动物的个体数等)不能太少，否则实验的结果不足以反映出生物学现象的本来面目。任何一项生物学实验，要有科学性，都必须能够重复，都必须经得起重复。 此外，还应注意科学性原则(指在设计实验时，必须要有充分的科学依据，也就是要to West rear, to County Shen Liqun report guerrillas breakout Hou of action situation, boat via Zhejiang wuxing daughter town Shi, six people has a NI surname "spies" (enemy) midway tuogu landing tipsters, away from small town three in Xu, was day Elves Li Taishan Department captured, five people all killed, broken corpse sank Yu River in the. On January 18, 1943, when the Japanese army militiamen arrested 53 people in Wuzhen, transferred to the tomb of the former Japanese military police command (in the "Tai" Jiang Yuan), the 28th in Shenyang North of jade bang massacred them. Hu Maosheng knife wounds woke up in the middle of them, crawling out from the dead, in the tomb of Gao Changhai residents, saved by bing. Such as Hu Maosheng, Gao Changhai is a witness to this tragedy. (B) in memory of "massacre" Xu Youyong yan tomb is the copper law. Copper originally was called Luo yan Tomb, because Eastern Han dynasty distinguished prose poems my father yan Tan bogey was buried in the town's water. Has a long history here, cultural atmosphere, and there are many old houses, and left many people with lofty ideals. Business flourished here, is the hub of four townships of agricultural and sideline products, wine culture has a long history. The outskirts of the town has left, "Huang Chi", originally Yue water hides 以前人的实验为基础，而不是凭空设想，主观臆造)、简便经济原则(如，装置简单、实验步骤较少、使用材料用具少、实验时间较短等)，等等。 2(2 探究性实验和验证性实验的比较 探究性实验 验证性实验 探索研究对象的未知属性、特征以及与其他验证研究对象的已知属性、特征实验目的 因素的关系 以及与其他因素的关系 假设一般采用“如果A，则B” 的形式表述，因结论是己知的，因此不存在假实验假设 是根据现有的科学理论、事实(对所要研究设问题 的对象设想出一种或几种可能性的解释 实验原理 因探究内容而异 因验证内容而异 应有的实验步骤实际上并未完成，因探究内实验步骤可以是曾经做过或尚实验过程 容而异 未做过的，因验证内容而异 实验现象 未知，可以不描述 已知，应准确描述 一般需讨论“如果出现结果?会怎样，如果实验现象是确定的，要么是，要实验结果的出现结果?或?又会怎样” 。但有时也会出么不是。 预测 现“预测最可能的结果”的问题(此种情况应 根据已有知识推测最合理的结果。 可根据可能出现的结果，做出不同的推论。根据实验结果做出肯定或否定实验结论 即，结论是不惟一的。 的结论。即，结论是惟一的。 探究性实验的例题:现有一植物的种子，已知它的萌发受水分、温度和氧气的影响，但不了解其萌发与光是否有关。为探究光的有无对该种子的萌发的影响，请你依据所给材料和用品设计出实验的方法步骤，预测可能的实验结果，并分别得出相应的结论。 (1)材料和用品:数量充足的铺有滤纸的培养皿、无菌水、表面消毒过的种子等。 (2)方法步骤: ? ; ? 。 (3)可能的实验结果及相应的结论: ? ; ? ; to West rear, to County Shen Liqun report guerrillas breakout Hou of action situation, boat via Zhejiang wuxing daughter town Shi, six people has a NI surname "spies" (enemy) midway tuogu landing tipsters, away from small town three in Xu, was day Elves Li Taishan Department captured, five people all killed, broken corpse sank Yu River in the. On January 18, 1943, when the Japanese army militiamen arrested 53 people in Wuzhen, transferred to the tomb of the former Japanese military police command (in the "Tai" Jiang Yuan), the 28th in Shenyang North of jade bang massacred them. Hu Maosheng knife wounds woke up in the middle of them, crawling out from the dead, in the tomb of Gao Changhai residents, saved by bing. Such as Hu Maosheng, Gao Changhai is a witness to this tragedy. (B) in memory of "massacre" Xu Youyong yan tomb is the copper law. Copper originally was called Luo yan Tomb, because Eastern Han dynasty distinguished prose poems my father yan Tan bogey was buried in the town's water. Has a long history here, cultural atmosphere, and there are many old houses, and left many people with lofty ideals. Business flourished here, is the hub of four townships of agricultural and sideline products, wine culture has a long history. The outskirts of the town has left, "Huang Chi", originally Yue water hides ? 。 解析:这是在高考试题中较早出现的具有探究性的实验方案设计。探究性实验是对某个生物学问题或实验结论不知道或不清楚～需要通过一定的实验方法～对可能出现的多个预期结果进行实验探究～从而得出实验结论。主要考查考生的实验设计、分析和评价的能力。其基本内容一般包括:明确实验目的、要求、条件,确定实验原理、研究对象、实验设计思路,设计实验操作步骤～以及对实验结果的多向预测和解释等。 参考答案:(1)?向培养皿中倒入适量的水，将等量的种子分别放入两组培养皿中 ?将一组置于有光照的环境中，另一组置于黑暗环境中，在培养过程中，使两组培养皿所处温度、水分、空气状况适宜且相同 (3)?有光组萌发，无光组也萌发(或发芽率差异不显著)，该种植物的种子的萌发不受光的影响;?有光组萌发，无光组不萌发(或有光组发芽率高于无光组，差异显著)，光是该种植物种子萌发的必要条件之一; ?有光组不萌发，无光组萌发(或无光组发芽率高于有光组，差异显著)，光抑制该种植物种子的萌发。 验证性实验的例题:血液中的钙离子在血液凝固过程中起重要作用，缺乏则血液不能凝固，草酸钾溶液能与血液中的钙离子发生反应，形成草酸钙沉淀，起抗凝作用。请根据提供的实验材料和用具，简要写出第二步以后的实验步骤和实验结果，验证钙离子在血液凝固中的作用，并回答问题。 一、实验材料和用具:(1)家兔 (2)生理盐水 (3)酒精棉 (4)适宜浓度的草酸钾溶液 (5)适宜浓度的氯化钙溶液 (6)试管、注射器(针管、针头) 二、实验步骤和实验结果 第一步:在A、B试管中分别加入等量的草酸钾溶液和生理盐水(见图) 第二步: 第三步: to West rear, to County Shen Liqun report guerrillas breakout Hou of action situation, boat via Zhejiang wuxing daughter town Shi, six people has a NI surname "spies" (enemy) midway tuogu landing tipsters, away from small town three in Xu, was day Elves Li Taishan Department captured, five people all killed, broken corpse sank Yu River in the. On January 18, 1943, when the Japanese army militiamen arrested 53 people in Wuzhen, transferred to the tomb of the former Japanese military police command (in the "Tai" Jiang Yuan), the 28th in Shenyang North of jade bang massacred them. Hu Maosheng knife wounds woke up in the middle of them, crawling out from the dead, in the tomb of Gao Changhai residents, saved by bing. Such as Hu Maosheng, Gao Changhai is a witness to this tragedy. (B) in memory of "massacre" Xu Youyong yan tomb is the copper law. Copper originally was called Luo yan Tomb, because Eastern Han dynasty distinguished prose poems my father yan Tan bogey was buried in the town's water. Has a long history here, cultural atmosphere, and there are many old houses, and left many people with lofty ideals. Business flourished here, is the hub of four townships of agricultural and sideline products, wine culture has a long history. The outskirts of the town has left, "Huang Chi", originally Yue water hides 第四步: 问题:设置B管的目的是 。 解析:该题所要验证的是血液中的钙离子在血液凝固过程中起重要作用。 从题中第一步知道～A、B两支试管中分别加入等量的草酸钾溶液和生理盐水。草酸钾能与血液中的钙离子形成草酸钙沉淀～起抗凝作用,而生理盐水则相当于人体内的细胞外液～不影响血液中钙离子的作用。因此～如果A、B两支试管中分别加入新鲜血液后～会出现A试管中血液不凝固,血液中的钙离子与草酸钾发生了反应,～B试管中血液凝固的现象。由B试管对照,第一次对照,组可说明～缺乏钙离子血液不凝固～有钙离子血液能凝固。 如何肯定是血液中的钙离子而不是其它物质在血液凝固中起作用,可由题中提供的材料再做一次对照,即第二次对照,实验。即在A试管发生沉淀之后加入一定量的氯化钙溶液～至钙离子完全与草酸钾发生反应～继续加入氯化钙就会发现A试管中血液发生了凝固。从A试管加入氯化钙前后的现象对比～便可以验证在血液凝固中起作用的是钙离子而非其它物质。 参考答案: 第二步:用酒精棉消毒(家兔耳廓缘静脉)，用注射器取兔血(1,2 mL) 第三步:立即将等量的鲜血分别加入到A、B试管中，经过一段时间后， 第四步:将等量的CaCl2溶液分别加入到A、B两试管中，结果:A管:凝固，B管:仍凝固。 问题:作为A管的对照。(未完待续, 高考理综生物学实验复习应该注意的几个问题(?) 四川绵阳第一中学 冯永康 在最近几年的高考理综生物学试题命制中，不仅十分明显地重视了对考试大纲中规定的教科书中17个必做实验的考查，也更加注重通过提供新的情境材料，较为全面地考查考生的实验与探究能力。 实验是高考重点考查的内容之一，它并非是一种专有题型。实验内容的考查可以是选择题，也可以是以各种图形或实验方案等形式呈现的非选择题。在高考理科综合能力测试to West rear, to County Shen Liqun report guerrillas breakout Hou of action situation, boat via Zhejiang wuxing daughter town Shi, six people has a NI surname "spies" (enemy) midway tuogu landing tipsters, away from small town three in Xu, was day Elves Li Taishan Department captured, five people all killed, broken corpse sank Yu River in the. On January 18, 1943, when the Japanese army militiamen arrested 53 people in Wuzhen, transferred to the tomb of the former Japanese military police command (in the "Tai" Jiang Yuan), the 28th in Shenyang North of jade bang massacred them. Hu Maosheng knife wounds woke up in the middle of them, crawling out from the dead, in the tomb of Gao Changhai residents, saved by bing. Such as Hu Maosheng, Gao Changhai is a witness to this tragedy. (B) in memory of "massacre" Xu Youyong yan tomb is the copper law. Copper originally was called Luo yan Tomb, because Eastern Han dynasty distinguished prose poems my father yan Tan bogey was buried in the town's water. Has a long history here, cultural atmosphere, and there are many old houses, and left many people with lofty ideals. Business flourished here, is the hub of four townships of agricultural and sideline products, wine culture has a long history. The outskirts of the town has left, "Huang Chi", originally Yue water hides 中，设计、评价和完成实验的能力考查居于越来越重要的位置。以考试大纲中第2项能力要求为主的4项能力，都与实验内容紧密相关，充分体现了生物学是一门以实验研究方法为主线的自然学科。 三、高考理综生物学实验的两种基本题型 1(以选择题的形式，对教科书中的实验内容进行综合性的考查 高考考试大纲规定的17个实验，具体包括“实验原理、方法步骤、预测分析和实验结论”等方面。以选择题形式考查教科书的实验，既可增大考试内容的覆盖面，也可进一步体现注重基础性、综合性、应用性以及思维量的考查，从而使选择题每小题6分的价值，得到了真正的体现，使生物学科在高考中的选拔性功能，得到了进一步的提高。 例1( 下列对实验的相关叙述，正确的是 A(探索淀粉酶对淀粉和蔗糖的专一性作用时，可用碘液替代斐林试剂进行鉴定 B(纸层析法分离叶绿体色素的实验结果表明，叶绿素b在层析液中溶解度最低 C(调查人群中某种遗传病的发病率时，应选择有遗传病史的家系进行调查统计 D(鉴定蛋白质时，应将双缩脲试剂A液和B液混合以后再加入待检组织样液中 解题的简要思路:这是多年来第一次将教科书中的实验和研究性课题～恰当组合成选择题的形式～对考生进行的多个必做实验的考查。 在A项中～用斐林试剂是来鉴定淀粉水解生成的还原糖,碘液只能用来鉴定淀粉存在与否～蔗糖遇碘液不会发生反应～因此达不到鉴定的目的。在B项中～根据“色素在层析液中的溶解度越大～随层析液在滤纸条上的扩散速率越快”的原理～～叶绿素b形成的色素带位于滤纸条的最下方～可判断出扩散最慢～溶解度最低。在C项中～调查人群中某种遗传病的发病率需要调查包括有遗传病史的家系在内的一个较大的群体,如一个社区,,而选择有遗传病史的家系进行调查统计～是调查该遗传病的遗传方式。在D项中～需要明确双缩脲试剂的正确使用是先加A液,NaOH溶液,～再加B液,CuSO溶液,。 4 答案:B 例2( 为了验证胰岛素具有降低血糖含量的作用，在设计实验时，如果以正常小鼠注射某种药物前后小鼠症状作为观察指标，则下列对实验组小鼠注射药物的顺序，正确的是 to West rear, to County Shen Liqun report guerrillas breakout Hou of action situation, boat via Zhejiang wuxing daughter town Shi, six people has a NI surname "spies" (enemy) midway tuogu landing tipsters, away from small town three in Xu, was day Elves Li Taishan Department captured, five people all killed, broken corpse sank Yu River in the. On January 18, 1943, when the Japanese army militiamen arrested 53 people in Wuzhen, transferred to the tomb of the former Japanese military police command (in the "Tai" Jiang Yuan), the 28th in Shenyang North of jade bang massacred them. Hu Maosheng knife wounds woke up in the middle of them, crawling out from the dead, in the tomb of Gao Changhai residents, saved by bing. Such as Hu Maosheng, Gao Changhai is a witness to this tragedy. (B) in memory of "massacre" Xu Youyong yan tomb is the copper law. Copper originally was called Luo yan Tomb, because Eastern Han dynasty distinguished prose poems my father yan Tan bogey was buried in the town's water. Has a long history here, cultural atmosphere, and there are many old houses, and left many people with lofty ideals. Business flourished here, is the hub of four townships of agricultural and sideline products, wine culture has a long history. The outskirts of the town has left, "Huang Chi", originally Yue water hides A(先注射胰岛素溶液，后注射葡萄糖溶液 B(先注射胰岛素溶液，再注射胰岛素溶液 C(先注射胰岛素溶液，后注射生理盐水 D(先注射生理盐水，后注射胰岛素溶液 解题的简要思路:本实验是验证胰岛素是否具有降低血糖含量的作用～因而有无胰岛素应该是实验中的唯一变量～也就是说～对照组中没有胰岛素～而实验组中应该有胰岛素～且注射胰岛素后血糖浓度应该与实验前发生变化。实验的操作步骤应该是:给对照组注射一定量的生理盐水～给实验组注射等量的用生理盐水溶解的胰岛素溶液,一段时间后观察两组小鼠的症状表现～可见对照组小鼠正常～而实验组小鼠出现血糖降低的症状～再给实验组小鼠注射一定浓度的葡萄糖溶液～可见实验鼠的症状得以恢复。 答案:A 2(以非选择题形式，常在新情境下进行变式考查 近年来，高考理综生物学试题也更加注重选用新的情境材料作为命题背景，通过设置成各种实验装置图、数据表、实验方案等形式的非选择题，从实验方法的选择、变量的确认、对照的设置、方案的完善、结果的预期、分析解释以及对实验原理的理解等方面，进行富有启迪、饶有智趣地巧妙设问，对“实验与探究能力”进行重基础、重分析、多方向、多层次的全方位考查。 例3( 研究发现，当土壤干旱时，根细胞会迅速合成某种化学物质X。有人推测根部合成的X运输到叶片，能调节气孔的开闭。他们做了如下实验:从同一植株上剪取大小和生理状态一致的3片叶，分别将叶柄下部浸在不同浓度X的培养液中。一段时间后，测得的有关数据如下表所示。(注:气孔导度越大。气孔开启程度越大) -3培养液中X的浓度/mol?m -5-35×10 5×10-4 5×10 -1叶片中X的浓度/mol?g(鲜重) 2(47 2(97 9(28 -2-1叶片中的气孔导度/mol?m?a 0(54 0(43 0(27 以上方案有不完善的地方，请指出来并加以修正。 to West rear, to County Shen Liqun report guerrillas breakout Hou of action situation, boat via Zhejiang wuxing daughter town Shi, six people has a NI surname "spies" (enemy) midway tuogu landing tipsters, away from small town three in Xu, was day Elves Li Taishan Department captured, five people all killed, broken corpse sank Yu River in the. On January 18, 1943, when the Japanese army militiamen arrested 53 people in Wuzhen, transferred to the tomb of the former Japanese military police command (in the "Tai" Jiang Yuan), the 28th in Shenyang North of jade bang massacred them. Hu Maosheng knife wounds woke up in the middle of them, crawling out from the dead, in the tomb of Gao Changhai residents, saved by bing. Such as Hu Maosheng, Gao Changhai is a witness to this tragedy. (B) in memory of "massacre" Xu Youyong yan tomb is the copper law. Copper originally was called Luo yan Tomb, because Eastern Han dynasty distinguished prose poems my father yan Tan bogey was buried in the town's water. Has a long history here, cultural atmosphere, and there are many old houses, and left many people with lofty ideals. Business flourished here, is the hub of four townships of agricultural and sideline products, wine culture has a long history. The outskirts of the town has left, "Huang Chi", originally Yue water hides 解题的简要思路:由于某种化学物质X能调节气孔的开闭。当土壤干旱时～根细胞会迅速合成某种化学物质X并运输到叶片发挥调节作用。在提供的实验方案和数据表中～通过对“叶片中X的浓度”和“测定叶片的气孔导度”等信息进行提取和处理～可理解某种化学物质X浓度的增大与该细胞的失水有关。 任何一个实验的设计～都必须体现:?“设立对照原则”～该实验缺少对照组～应增加1组空白对照,即～将叶片的叶柄下部浸在不含化学物质X的培养液中,。?“平行重复原则”～该实验方案所取样本太小,仅剪取了3片叶,～实验结果便可能具有一定的偶然性。要得到令人信服的实验结果～应该要有较大的样本量～该实验应“取叶片若干～等分为三组”为宜。 答案: a(样本量太小。应“取叶片若干，等分为三组”。 b(缺乏空白对照。增加1组，将叶片的叶柄下浸在不含X的培养液中。 例4.从某植物长势一致的黄化苗上切取等长幼茎段(无叶和侧芽)。自茎段顶端向下对称纵切至约3/4处。将切开的茎段浸没在蒸馏水中。一段时间后，观察到半边茎向外弯曲生长，如图所示。若上述黄化苗茎段中的生长素浓度是促进生长的，放入水中后半边茎内、外两侧细胞中的生长素浓度都不会升高。请仅根据生长素的作用特点分析半边茎向外弯曲生长这一现象，推测出现该现象的两种可能原因。 原因1是 。 原因2是 。 解题的简要思路:该题通过从长势一致的黄化苗上切取等长幼茎段进行的如图处理～考查考生对生长素促进生长作用和作用特点的认知。生长素与植物生长的关系既与生长素浓度大小有关～也与植物体不同部位对同一浓度生长素敏感性不同有关。 通过阅读题干文字叙述提供的信息～可以分析依次得出:,1,幼茎段无叶和侧芽～因此不会再有新的生长素来源,,2,黄化苗茎段中的生长素浓度是促进生长的～放入水中后半边茎内、外两侧细胞中的生长素浓度都不会升高～说明只需考虑低浓度的促进效应～没to West rear, to County Shen Liqun report guerrillas breakout Hou of action situation, boat via Zhejiang wuxing daughter town Shi, six people has a NI surname "spies" (enemy) midway tuogu landing tipsters, away from small town three in Xu, was day Elves Li Taishan Department captured, five people all killed, broken corpse sank Yu River in the. On January 18, 1943, when the Japanese army militiamen arrested 53 people in Wuzhen, transferred to the tomb of the former Japanese military police command (in the "Tai" Jiang Yuan), the 28th in Shenyang North of jade bang massacred them. Hu Maosheng knife wounds woke up in the middle of them, crawling out from the dead, in the tomb of Gao Changhai residents, saved by bing. Such as Hu Maosheng, Gao Changhai is a witness to this tragedy. (B) in memory of "massacre" Xu Youyong yan tomb is the copper law. Copper originally was called Luo yan Tomb, because Eastern Han dynasty distinguished prose poems my father yan Tan bogey was buried in the town's water. Has a long history here, cultural atmosphere, and there are many old houses, and left many people with lofty ideals. Business flourished here, is the hub of four townships of agricultural and sideline products, wine culture has a long history. The outskirts of the town has left, "Huang Chi", originally Yue water hides 有高浓度的抑制效应,,3,仅根据生长素的作用特点分析半边茎向外弯曲生长这一现象～可分析得出造成这一现象的原因主要是半边茎内外两侧的细胞对同一浓度的生长素敏感性不同。 答案: 原因1:内侧细胞中的生长素浓度比外侧高，所以内侧细胞生长较快。 原因2:内外两侧细胞中的生长素浓度相同，但内外侧细胞对生长素敏感性不同，该浓度的生长素更有利于内侧细胞的生长 高考理综生物学实验内容的考查尽管形式多样，能力要求也相对较高，但对任何一个实验方案的设计，都有基本相同的实验操作程序(即:?取材分组编号;?单一变量处理;?适宜条件培养;?观察预测解释)，因此也有基本相同的解题思路。 在高考理综生物学复习的全过程中，要有针对性地对高考实验试题进行诊断和把脉，通过高考实验的系统性、专题性的基本功训练，增强考生对生物学实验思想、实验方法、实验操作技术的认知，提高应对高考实验的实战方法和技巧。 面对2011年的高考，我们必须认真反思高考生物学复习过程中的得与失，充分重视实验内容考查在高考中所具有的举足轻重的地位。“成也实验，败也实验”，这是近年许多参加过高考考生的切身体会。,全文完, 2011 to West rear, to County Shen Liqun report guerrillas breakout Hou of action situation, boat via Zhejiang wuxing daughter town Shi, six people has a NI surname "spies" (enemy) midway tuogu landing tipsters, away from small town three in Xu, was day Elves Li Taishan Department captured, five people all killed, broken corpse sank Yu River in the. On January 18, 1943, when the Japanese army militiamen arrested 53 people in Wuzhen, transferred to the tomb of the former Japanese military police command (in the "Tai" Jiang Yuan), the 28th in Shenyang North of jade bang massacred them. Hu Maosheng knife wounds woke up in the middle of them, crawling out from the dead, in the tomb of Gao Changhai residents, saved by bing. Such as Hu Maosheng, Gao Changhai is a witness to this tragedy. (B) in memory of "massacre" Xu Youyong yan tomb is the copper law. Copper originally was called Luo yan Tomb, because Eastern Han dynasty distinguished prose poems my father yan Tan bogey was buried in the town's water. Has a long history here, cultural atmosphere, and there are many old houses, and left many people with lofty ideals. Business flourished here, is the hub of four townships of agricultural and sideline products, wine culture has a long history. The outskirts of the town has left, "Huang Chi", originally Yue water hides