植物细胞的有丝分裂

植物细胞的有丝分裂 第九章 生命的延续 第一节 有丝分裂 科目:生命科学 讲课班级:高二(3)班 教师姓名:徐娟 背景分析: 【教材分析】 细胞的有丝分裂是生命科学第九章的重点内容和基础内容之一。本节主要包括细胞增殖的意义、细胞周期、动植物细胞有丝分裂的过程等内容，是本章后续学习减数分裂和细胞的分化的知识铺垫和重要基础，也与遗传物质和遗传信息的传递有密不可分的关系。 【学情分析】 高二学生的特点是抽象思维能力和综合思维能力较强，同时，对生物课程的学习，也有着浓厚的兴趣。他们在初中曾学过“细胞通过分裂产生新细胞”的内容，但是对此了解得很浅，没有深入到细胞分裂的具体过程。因此，教学中可以利用学生的知识基础并遵循学生的认知规律，通过适当的教学策略，使新知识有效地整合进学生原有的知识网络中，使学生的知识体系得到丰富和发展。 教学目标 (一) 知识与技能: , 能够准确描述细胞周期的概念，知道细胞周期中分裂间期时间较长; , 能够准确指出植物细胞有丝分裂最旺盛的部位; , 能够用自己的语言 总结 初级经济法重点总结下载党员个人总结TXt高中句型全总结.doc高中句型全总结.doc理论力学知识点总结pdf 出分裂期各时期的特点，能辨认处于有丝分裂后期的细胞; (二) 过程与方法: , 通过观看动画，锻炼观察能力和分析比较能力; , 通过参与课堂提问，增强自身表达能力， 规范 编程规范下载gsp规范下载钢格栅规范下载警徽规范下载建设厅规范下载 使用生物学语言; (三) 情感、态度、价值观: , 通过学习，体验生命科学的奥妙和严谨; , 积极参与小组讨论，增强团队精神; 教学重点: 植物细胞有丝分裂各时期的特点; 有丝分裂细胞周期的概念 教学难点: 有丝分裂各时期细胞的辨认; 教具、仪器和媒体: 多媒体 课件 超市陈列培训课件免费下载搭石ppt课件免费下载公安保密教育课件下载病媒生物防治课件 可下载高中数学必修四课件打包下载 、图片、植物细胞有丝分裂演示动画; 教学策略 1 教法选择:采用启发式教学，引导学生观察对比，从而得出结论。 以往对有丝分裂这部分的教学采取的是教师传授为主的教学方式，教师将细胞分裂各时期的特点进行归纳，然后学生被动接受。一方面学生对过程不一定理解，掌握起来比较困难;另一方面学生是被动接受，总是提不起兴趣。现在我选择合适的演示动画，让学生通过观察和对比说出在细胞分裂过程中细胞内的变化，教师仅仅在语言规范方面给予指导，学生才是学习的主体，这样的教学设计既锻炼了学生的观察能力又降低了学习的难度，体现将课堂还给学生的教学理念。 fertility better. Site preparation before planting, clearing rubble, if conditions for soil disinfection can be carried out. Thickness of planting soil: Arbor thickness not less than 90cm, shrubs not less than 60cm, to be not less than 20cm. Poor quality of the soil, should enlarge the hole (hole) specifications, and debris picked up by clearing encountered lime slag, against the growth substances such as stone, asphalt, you should pit (hole) diameter increased 1 to twice times, harmful substances removal clean and put on suitable planting soil. F, green natural trees found in the planting hole dug seriously affect the operation of the underground obstacle, get in touch with designers, the appropriate changes. ?, seedling quality of trees dug a well ... C, trees have been delivered to the site in a given place, to turn the roots covered with straw to prevent water loss. ? trees planted seedlings before planting quality requirements: should be checked according to the design drawings and seedling varieties, specifications and plant location. Principles of plant "outside the high to low, the first after the first" grown order "big tree---small tree---shrub-plants" before the tree into planting holes, you should check the planting hole size and depth, while root system requirements are not met, trimming plants dibble. A, seedling rate should be commensurate with the speed of planted seedlings, planted along, kind of finish, minimizing root exposure. On planting trench, remaining seedling exposed roots should be kept buried with soil. B, depending on the specific seedlings, good seedlings and planting depth should be identified, roots with soil plug solid rear mud balls can be under the 2 教具的选择:合理有效地运用多媒体技术。 有丝分裂是一个生命现象，是动态的，以往的教学常用挂图做教具，很难使学生理解有丝分裂是一个连续的过程，而本堂课采用的植物细胞有丝分裂的动画使学生既可以认识到有丝分裂是个动态的、连续的变化又可以直观的观察到细胞内的变化，生动形象，能够激发学生的兴趣，调动学生的学习积极性。 有丝分裂的动画资源还是比较丰富的，我选择了其中比较符合我的教学设计的两个，一个是显微镜下真实拍摄到的细胞分裂的过程，细胞内染色体的变化比较清晰但是很短暂，学生通过观看可以对有丝分裂有一个宏观的认识，意识到细胞的分裂是一个连续的过程。另一个植物细胞的有丝分裂动画，这个动画可以分节演示，适合学生对分裂中各时期的现象进行对比观察，而且动画中细胞的各个结构都用鲜艳的颜色表示出来，很容易区分，降低了观察的难度。 3 难点的处理:动态静态相互转化。 在总结植物细胞有丝分裂各时期的特点后接着让学生画出各时期细胞，这样可以检验学生对各时期特点的掌握情况，又可以强化对各时期细胞图的辨认;动画的动态过程转变为相 增强学生的应变能力，最后再让学生互相评价和自我评价对应的具有典型特征的静态图片， 以加深印象。 板 书 关于书的成语关于读书的排比句社区图书漂流公约怎么写关于读书的小报汉书pdf : 第一节 有丝分裂 一、植物细胞有丝分裂的过程 1、 观察部位:根尖(茎尖)分生组织 2、 分裂间期:染色质内DNA的复制和有关蛋白质的合成 3、 分裂期 前:出现染色体，出现纺锤丝形成的纺锤体。核膜解体，核仁消失。染色体在细胞 中散乱排列。 中:在纺锤丝牵引下，染色体的着丝点排列在细胞中央的一个平面上(赤道面)。 后:着丝点分裂，姐妹染色单体分离，成为两个染色体，在纺锤丝的牵引下，分别 向细胞两极移动，此时细胞染色体数目暂时加倍。 末:染色体解旋成细丝状，纺锤体消失，新的核膜和核仁出现。赤道板位置出现细 胞板，并逐渐扩展形成新的细胞壁。 二、细胞周期 时间安排: 引入 植物细胞有丝分有丝分裂的意义 细胞周期 课堂练习 裂的过程 2分钟 22 3分钟 5分钟 8分钟 fertility better. Site preparation before planting, clearing rubble, if conditions for soil disinfection can be carried out. Thickness of planting soil: Arbor thickness not less than 90cm, shrubs not less than 60cm, to be not less than 20cm. Poor quality of the soil, should enlarge the hole (hole) specifications, and debris picked up by clearing encountered lime slag, against the growth substances such as stone, asphalt, you should pit (hole) diameter increased 1 to twice times, harmful substances removal clean and put on suitable planting soil. F, green natural trees found in the planting hole dug seriously affect the operation of the underground obstacle, get in touch with designers, the appropriate changes. ?, seedling quality of trees dug a well ... C, trees have been delivered to the site in a given place, to turn the roots covered with straw to prevent water loss. ? trees planted seedlings before planting quality requirements: should be checked according to the design drawings and seedling varieties, specifications and plant location. Principles of plant "outside the high to low, the first after the first" grown order "big tree---small tree---shrub-plants" before the tree into planting holes, you should check the planting hole size and depth, while root system requirements are not met, trimming plants dibble. A, seedling rate should be commensurate with the speed of planted seedlings, planted along, kind of finish, minimizing root exposure. On planting trench, remaining seedling exposed roots should be kept buried with soil. B, depending on the specific seedlings, good seedlings and planting depth should be identified, roots with soil plug solid rear mud balls can be under the 教学过程: 教学内容 教师行为 学生行为 一、植物细胞由三个问题引入新课 思考并得出结论:生物的生长 有丝分裂1、为什么洗过手后没过多久手上和繁殖离不开细胞分裂和分化。 的过程 的细菌数量又会增加? 观看视频，加深对细胞分裂使 2、为什么修剪过的草坪不久又需单细胞生物个数增加的认识。 要修剪呢? 3、为什么洗过头发没几天又会有 头皮屑? 细胞分裂的方式有三种:无丝分知道有丝分裂是生物体细胞分裂，有丝分裂，减数分裂。有丝分裂裂的主要形式。 是绝大多数生物组成身体的细胞进行 分裂的主要形式。由于分裂过程中有 纺锤丝出现所以得名。 提问:如果要观察植物细胞的有联系植物体内生长素的合成部丝分裂,你会选择植物的哪部分为观察位说出:选择生长旺盛的部位。 对象呢?为什么? 植物细胞有丝分裂观察部位:根 尖(茎尖)分生组织。 引导学生比较植物根尖不同区域通过比较，能够说处分生区内的放大图，进一步说明为何选择分生部发生变化的细胞数目最多;比较区为观察对象。 分生区的细胞能够发现并不是所有 的细胞都处于分裂状态。 提问:此刻没有在分裂的细胞它思考并说出:为细胞分裂作准们会分裂吗,现在它们在干什么, 备或完成分裂在休息。 细胞分裂前的准备阶段称为分裂 间期，主要进行染色质内DNA的复制 和有关蛋白质的合成。 回顾细胞的结构和染色体、染 为什么要进行DNA的复制,(复色质等基本概念。 习相关知识) 染色质和染色体的基本关系:同观看动画，理解染色质和染色一物质在不同时期的两种形态。 体的关系。 演示视频:细胞分裂的真实过程 树立细胞分裂是一个连续过程 解释为了方便学习和研究我们依的观念。 据染色体的变化特点将分裂期又划分 为前、中、后、末四期。 反复播放分节动画，帮助学生总学生观察比较后得出: 前:出现染色体，出现纺锤丝形成结各时期的变化特点 fertility better. Site preparation before planting, clearing rubble, if conditions for soil disinfection can be carried out. Thickness of planting soil: Arbor thickness not less than 90cm, shrubs not less than 60cm, to be not less than 20cm. Poor quality of the soil, should enlarge the hole (hole) specifications, and debris picked up by clearing encountered lime slag, against the growth substances such as stone, asphalt, you should pit (hole) diameter increased 1 to twice times, harmful substances removal clean and put on suitable planting soil. F, green natural trees found in the planting hole dug seriously affect the operation of the underground obstacle, get in touch with designers, the appropriate changes. ?, seedling quality of trees dug a well ... C, trees have been delivered to the site in a given place, to turn the roots covered with straw to prevent water loss. ? trees planted seedlings before planting quality requirements: should be checked according to the design drawings and seedling varieties, specifications and plant location. Principles of plant "outside the high to low, the first after the first" grown order "big tree---small tree---shrub-plants" before the tree into planting holes, you should check the planting hole size and depth, while root system requirements are not met, trimming plants dibble. A, seedling rate should be commensurate with the speed of planted seedlings, planted along, kind of finish, minimizing root exposure. On planting trench, remaining seedling exposed roots should be kept buried with soil. B, depending on the specific seedlings, good seedlings and planting depth should be identified, roots with soil plug solid rear mud balls can be under the 的纺锤体。核膜解体，核仁消失。 染色体在细胞中散乱排列 中:在纺锤丝牵引下，染色体的着 丝点排列在细胞中央的一个平面上 (赤道面)。 后:着丝点分裂，姐妹染色单体分 离，成为两个染色体，在纺锤丝的 牵引下，分别向细胞两极移动，此 时细胞染色体数目暂时加倍。 末:染色体解旋成细丝状，纺锤体 消失，新的核膜和核仁出现。赤道 板位置出现细胞板，并逐渐扩展形 成新的细胞壁。 教师归纳总结并提出细胞有丝分 裂的意义:亲代细胞的染色体先经过 复制，再平均分配到两个子细胞中，学生体会有丝分裂的意义。 从而保证了亲、子两代细胞中含有相 同数目和形态结构的染色体。 二、细胞周期 理解细胞周期的概念，并且通过比像根尖分生组织这样的细胞保持 较 表格 关于规范使用各类表格的通知入职表格免费下载关于主播时间做一个表格详细英语字母大小写表格下载简历表格模板下载 数据知道分裂间期总是长于 着旺盛的分裂能力，这样的连续分裂分裂期的。 的细胞经历着:分裂间期——分裂期细胞周分裂间分裂 ——分裂间期——分裂期……这样的期(h) 期(h) 期(h) 循环，我们又说这样的细胞具有细胞蛙单倍体胚细36.9 35.3 1.6 周期。对于连续分裂的细胞，从一次胞 分裂完成到下一次分裂完成之间的过蚕豆根尖细胞 17.3 15.3 2 程，我们称为一个细胞周期。 人囊胚细胞 19.5 18.5 1 提问:为什么分裂间期需要那么紫鸭跖草根尖 20 17.5 2.5 小鼠十二指肠15.3 13.5 1.8 长时间, 细胞 提问:在显微镜下观察洋葱根尖 仓鼠卵细胞 12.4 11.6 0.8 分生组织细胞，处于什么时期的细胞 最多,为什么, 提问:你还能从这张图中找出哪 些时期的细胞, 三、课堂练习 活动一:完成课堂反馈练习 完成课堂练习 活动二:两人为小组绘制分裂期中一自我评价和小组互评 个时期的细胞模式图 fertility better. Site preparation before planting, clearing rubble, if conditions for soil disinfection can be carried out. Thickness of planting soil: Arbor thickness not less than 90cm, shrubs not less than 60cm, to be not less than 20cm. Poor quality of the soil, should enlarge the hole (hole) specifications, and debris picked up by clearing encountered lime slag, against the growth substances such as stone, asphalt, you should pit (hole) diameter increased 1 to twice times, harmful substances removal clean and put on suitable planting soil. F, green natural trees found in the planting hole dug seriously affect the operation of the underground obstacle, get in touch with designers, the appropriate changes. ?, seedling quality of trees dug a well ... C, trees have been delivered to the site in a given place, to turn the roots covered with straw to prevent water loss. ? trees planted seedlings before planting quality requirements: should be checked according to the design drawings and seedling varieties, specifications and plant location. Principles of plant "outside the high to low, the first after the first" grown order "big tree---small tree---shrub-plants" before the tree into planting holes, you should check the planting hole size and depth, while root system requirements are not met, trimming plants dibble. A, seedling rate should be commensurate with the speed of planted seedlings, planted along, kind of finish, minimizing root exposure. On planting trench, remaining seedling exposed roots should be kept buried with soil. B, depending on the specific seedlings, good seedlings and planting depth should be identified, roots with soil plug solid rear mud balls can be under the 教学反思: 本堂课采用的植物细胞有丝分裂的动画进行教学，使学生对微观的生命现象有了更直观地认识，学生认识到细胞的有丝分裂是个动态的、连续变化的过程，并且通过观察细胞内的变化理解有丝分裂过程中的基本知识点和关键变化，更好的激发学生的兴趣，调动学生的学习积极性。 教师选择的辅助动画比较典型，既可以使学生通过观看对有丝分裂有一个宏观的认识，意识到细胞的分裂是一个连续的过程。又可以使学生对有丝分裂过程进行分节学习，适合学生对分裂中各时期的现象进行对比观察，而且动画中细胞的各个结构都用鲜艳的颜色表示出来，很容易区分，降低了观察的难度。 本堂课对于教学难点的处理不同于以往的传统教学，不是教师告诉学生“是什么”，而是学生告诉教师“发现了什么，看到了什么”这一转变其实正是体现了“还课堂给学生，以学生学习为本”的二期课改新理念。 教师在以后的教学中应该在问题的设计和如何使问题设计更具层次这一方面多下功夫，以期达到更好的教学效果。 fertility better. Site preparation before planting, clearing rubble, if conditions for soil disinfection can be carried out. Thickness of planting soil: Arbor thickness not less than 90cm, shrubs not less than 60cm, to be not less than 20cm. Poor quality of the soil, should enlarge the hole (hole) specifications, and debris picked up by clearing encountered lime slag, against the growth substances such as stone, asphalt, you should pit (hole) diameter increased 1 to twice times, harmful substances removal clean and put on suitable planting soil. F, green natural trees found in the planting hole dug seriously affect the operation of the underground obstacle, get in touch with designers, the appropriate changes. ?, seedling quality of trees dug a well ... C, trees have been delivered to the site in a given place, to turn the roots covered with straw to prevent water loss. ? trees planted seedlings before planting quality requirements: should be checked according to the design drawings and seedling varieties, specifications and plant location. Principles of plant "outside the high to low, the first after the first" grown order "big tree---small tree---shrub-plants" before the tree into planting holes, you should check the planting hole size and depth, while root system requirements are not met, trimming plants dibble. A, seedling rate should be commensurate with the speed of planted seedlings, planted along, kind of finish, minimizing root exposure. On planting trench, remaining seedling exposed roots should be kept buried with soil. B, depending on the specific seedlings, good seedlings and planting depth should be identified, roots with soil plug solid rear mud balls can be under the