浅谈“以问导学”在生物教学中的应用.docx

以问导学的方式已经成为生物课堂教学的一种重要方法，它以问题为中心，学生在教师指导下发现问题、提出问题、找到解决问题的办法，并通过活动找到答案，从而获得相关知识。作者根据自己的教学实践，结合生物教学的特点，在提高课堂教学的有效性上，探索新的生物教学的有效方法，科学地设计问题串，积极开展以问导学，做了一些尝试。一、如何设置问题（一）创设问题情境 产生冲突通过呈现问题情境以引发学生的认知冲突，使学生独立地发现问题是问题教学的重要环节。1.联系已有知识，产生认知冲突。影响学习的最重要的因素就是学生已经知道了什么，教师联系学生已学过的知识，设计问题，有意识地使学生产生认知冲突，进而提出问题，提高学习新内容的兴趣。例如，在生长素的生理作用一节，学生已经知道植物的向光性是因为生长素横向运输，在下部分布不均造成。生长素有促进植物生长的特点。导入新课时，展示植物横放的图片，提问：植物将如何生长？在回答根向上弯曲生长时，与他们熟知的生活常识根向地生长产生矛盾，教师此时展示生长素生理作用曲线图，既能巩固以前所学的知识，也能达到引导学生探究的目的。2.利用学生熟悉的事例， 联系生活实际。学生熟悉的实例和生活实际是很好的教学素材，讲授新课程由这些事例入手能快速集中学生的注意力，进入新内容。 如在讲基因突变时，教师展示蜘蛛侠图片，提出问题：被变异蜘蛛咬到真的会导致人基因突变吗？基因突变是怎样发生的，有什么特点？学生的积极性立即被调动，参与度提高。3.利用生物学或社会前沿热点问题。社会在发展，我们面临的社会问题也在增多，而很多与生物有着紧密的联系，如变性人、转基因食品及二胎问题等等。学生对这些有着极大的兴趣，所以，教师可引进生物方面的热点时事，作为生物教学的发酵剂，在课堂讲解后设置一些密切联系社会热点或现实的问题，让学生利用生物学知识分析解决问题，提高生物课堂的应用性，提高学生生物学习的兴趣。（二）围绕教学目标、教学重难点，设计有思考价值的问题教师在教学中可以将教学目标细化成教学问题，通过教学问题来解决教学的重难点，克服学生的思维障碍。例如，在教学“通过激素的调节”时，介绍过相关激素的类型作用，我先后提出下面的问题：看过现实版的小矮人吗？个子矮可能与什么激素有关？一定是激素方面的问题吗？太监和人妖有什么特点，是如何形成的，能生育吗？通过以上问题，学生就会在了解各种激素的作用的基础上，更进一步去思考激素的功能和特点，有利于突破本节课重难点。（三）优化问题的内容、结构、层次性根据学生的年龄和知识水平，对于整体性较强的内容，可分解成几个小问题，逐一提出，既达成教学目标，又注意了学生思维能力的培养。比如，在讲“生长素的发现”时， 先展示前两个实验，提出：实验中自变量是什么？胚芽鞘的弯曲与哪个部位有关？然后展示后两个实验再问：胚芽鞘感受单侧光刺激的部位和向光弯曲的部位分别是哪里？最后提出：根据实验，你能对向光性做出解释吗？这样学生在观察分析之后，得出答案，并在此过程中培养他们的逻辑性思维。（四）启发学生思维“授之以鱼，不如授之以渔。”教学过程中，教师通过问题引导学生思考，培养学生思维能力。例如，“物质跨膜运输的实例”中，学生阅读“问题探讨”，思考讨论教材中问题，教师可补充提问，“用塑料袋代替玻璃纸液面会升高吗？”“纱布、塑料袋与玻璃纸有何区别？”“清水换成高浓度的蔗糖溶液，结果会怎样？”引导学生思考扩散、半透膜、溶液浓度的重要性，进而得出本节重点渗透作用及其条件。之后提出“如果膜两侧分别是质量浓度都为30%的葡萄糖溶液和淀粉溶液，液面会不会变化？”这样设置既解决了重难点，又启发了学生思维，培养学生透过现象看本质的意识。二、“以问导学”过程中应注意的问题（一）难度梯度和节奏前苏联教育家赞可夫指出：设计问题要给学生以适当的负担。我们设计的问题要遵循学生的最近发展区，提出难易适中的问题，让学生跳一跳，够得到，并把握课堂节奏，把握好抛出问题及给出解答的时机。（二）问题的设置应能引发学生产生新的疑问。好的促进者不会限制学生对各种可能的未知领域的探索，但他会精心地把学生引导到问题空间的关键侧面，从而更好地利用问题所提供的学习机会。教师应通过有价值的问题，让学生自觉、主动的参与，发现并解决问题，再不断地生成问题，促进学生知识的建构。（三）及时评价，做好归纳总结课堂提问中，教师必然要得到学生的回答，这正是又一个促进学生学习提高的机会。教师要及时地给以评价，引导学生作出归纳总结。三、结语皮亚杰说过：一切真理都要学生自己获得，或者由他直接发现。至少由他重建，而不是简单地传递。“以问导学”的运用能发挥学生的主体性，教师在教学活动中设计、引导，使学生对知识的理解和感悟逐步深入，学生的能力得到培养和提高。每个人都有自己的见解和处理方式，因此，如何达到优良效果，我们还要在实践中不断改进修正。In the form of q learning has become an important method of classroom teaching, it centered on the problem, under the guidance of students in teachers found the problem, ask questions, find a solution to the problem, and find the answer through the activities, in order to gain knowledge. The authors according to their own teaching practice, combining the characteristics of biological teaching, in order to increase the effectiveness of classroom teaching, explore new effective method of biological teaching, scientifically design problems, actively carry out to ask tutorship, made some attempts.A, how to set up the problem(a) creating problem situationThrough the present situation to trigger the students cognitive conflict, causes the student to independently found that the problem is an important part of the problem teaching.1. Contact with prior knowledge, cognitive conflict. The most important factors influencing learning is what students already know, contact the knowledge students have learned teachers, design problem, consciously make students produce cognitive conflict, and then put forward problems, improve the interest in learning new content.In auxin physiological role of section, for example, students already know plant phototropism because auxin, horizontal transportation in the lower part of distribution. The characteristics of the growth is to promote plant growth. To import new lesson, the images of the plant askew, lift to ask: how will the plants grow? In response to a root bending upwards growth, and their familiar life common sense of the root to the growing conflict, teachers show auxin physiology curve at this time, can not only consolidate the previously learned knowledge, also can achieve the purpose of guide students to explore.2. The use of students familiar with the case, contact the actual life. Students familiar with the actual instance and the life is very good teaching material, teaching the new curriculum by these examples of can quickly focus the attention of students, into the new content. Such as talking about gene mutation, the teacher show spiderman images, a question: is the spider bite really can cause people to the mutated gene mutation? How genetic mutations happened, what is the distinguishing feature? The enthusiasm of students was immediately mobilize participation improvement.3. The use of biological or social frontier hot issues. In the development of society, we are faced with the social problems are on the rise, and many are closely linked with the life, such as transgender, genetically modified food, and two problems, and so on. Students have great interest on these, so, teachers can introduce the biological aspects of the hot spot of current affairs, as starter cultures of biological teaching, set up some closely related social hot spot after lectures or reality, let the students use biology knowledge analysis to solve problems, improve the applicability of biology classroom, improve the students interest in biology study.(2) around teaching target, teaching difficult point, has value of thinking design problemTeachers in the teaching of teaching target can be refined into teaching, through the teaching problems to solve the difficult point of teaching, to overcome the students thinking obstacles. For example, when teaching through the regulation of hormone, introduced the type of related hormone action, I have the following questions: seen reality version of the little man? Is short may be associated with any hormone? Must be hormonal problems? What is the distinguishing feature of the eunuch and transvestite, is how to form, fertile? Through the above problems, the students will be on the basis of understanding the role of various hormones, and further to ponder the function and characteristics of hormone, is helpful to break through the difficult point in this lesson.(3) the optimization of content, structure, hierarchyAccording to students age and knowledge level, with the strong overall content, can be broken down into several small problems, one by one, is to achieve the teaching goal, and pay attention to the cultivation of students thinking ability. For example, when talking about the discovery of auxin, first show the first two experiments, put forward: variables in the experiment? Coleoptile bending is related to what part? Then show after two experiments asked again, coleoptile feeling of unilateral light stimulate parts and to bend light parts are respectively? Finally, according to the experiment, you can explain phototropism? So students after observation analysis, get the answer, and cultivate their logical thinking in the process.(4) to inspire students thinkingTo teach a fish, is better than to fish. In the process of teaching, the teacher through questions to guide students thinking, cultivate students thinking ability. For example, in instance material transmembrane transport, students read problem, thinking to discuss issues in the textbooks, teachers can be added to ask questions, use plastic bags instead of cellophane level will rise? Whats the difference between the gauze with cellophane, plastic bags? Clear water with high concentration of sucrose solution, as a result, meeting how? Guide the students to think about diffusion, the importance of a semipermeable membrane, concentration of solution, this section focus on osmosis and its conditions are obtained. After put forward if the side of the membrane, respectively is mass concentration of 30% glucose solution and starch solution, liquid level can change? This set is solved the difficult point and inspire the students thinking, to cultivate students see the essence through the phenomenon of consciousness.Second, in the process of learning to ask problems should be paid attention to(a) difficulty gradient and rhythmThe former Soviet union educator praise can be pointed out that: the design problems with proper burden to students. Problem we design should follow the recent developments of students, bring up the question of moderate difficulty, let the students jump jump, get enough, and grasp the rhythm of classroom, grasp the timing of the throw questions and answers.(2) the problem of setting should be able to cause students to create new questions.Good facilitator doesnt restrict students to explore in the field of all kinds of possible unknown, but he will carefully to conduct the students to the key of the problem space profile, to better utilization of the learning opportunities provided. Teachers should through the valuable problem, lets the student con