First, the position and role of the textbook "Meixx" Senior High School Biology Chapter 3 Section 1 Part 2. This part is not only the key content of the third chapter, but also one of the key contents of the book. It is based on the knowledge of cytology, chromosomes, sericulture and breeding species. Through learning, students can fully understand the type, essence and significance of cell XX, and lay a cytological foundation for future learning about genetic variation and biological evolution.
Second, the teaching objectives
1. Knowledge Objective: To master the concept of meiosis XX and the process of sperm formation; Understand the significance of meiosis XX and fertilization.
2. Ability goal: To cultivate students' ability to read and draw pictures, and to compare, analyze and summarize by observing the behavior changes of chromosomes during meiosis XX.
3. Moral education goal: By studying the significance of Mei xx and fertilization, we can deepen our understanding of the changing law of things themselves and cultivate the viewpoint of unity of opposites and development and change.
Three. Teaching Emphasis, Difficulties and Determination Basis
1, teaching focus: the concept and process of reducing XX. This is the basis of germ cell formation, heredity, variation and cytology.
2. Teaching difficulties: the concepts of homologous chromosomes and tetrads and the changing rules of chromosome behavior, in which the changing rules of chromosome behavior are both difficult and important. Beginners lack perceptual knowledge about this and it is difficult to grasp the essence.
Fourth, the teaching material processing.
According to the difficulties of the textbook, the actual situation of students and the characteristics of multimedia courseware to transmit information, I arranged two class hours for this part. The first lesson is to learn the concept of meiosis XX, the process of sperm formation, the significance of meiosis XX and fertilization. In the second class, I studied the process of egg formation and compared the similarities and differences between meiosis XX and filariasis XX. This paper mainly explains the teaching method and process of the first class.
Teaching methods and means of verbs (abbreviation of verb)
Using multimedia courseware to create a vivid teaching atmosphere, at the same time, using narrative method, conversation method, comparison method and reading guidance method to guide students to think about a series of problems, make them actively participate in teaching, and cultivate students' ability of observation, comparison and summary while acquiring knowledge. While acquiring knowledge, cultivate students' ability of observation, comparison and summary.
Sixth, the specific teaching process.
Divided into two parts
Part I: Introduction.
First of all, introduce questions and make people think.
(1) What is sexual reproduction?
(2) What are the main ways?
After the answer, demonstrate the reproduction process of the egg, that is, fertilization, remind students to pay attention to the chromosome composition in the fertilized egg, and design an animation to simulate the combination process of sperm and egg, so as to further observe the chromosome characteristics in the fertilized egg. In this way, students can clearly see from the picture that half of the chromosomes in a fertilized egg come from sperm and half from egg cells, and the size and shape of every two chromosomes are similar, which leads to the concept of homologous chromosomes. In order to further illustrate the characteristics of homologous chromosomes, we insert the chromosome map of human somatic cells and finally get a complete concept. Homologous chromosome is the focus and breakthrough point of this topic. In the teaching arrangement, describing the concept of homologous chromosomes in advance is to disperse the difficulties and lay the foundation for discussing synapses and tetrads later.
Because the chromosomes of sperm and eggs are only half of those of fertilized eggs, that is, somatic cells, it naturally leads to the problem of how sperm and eggs are produced. Please discuss it first, can it be produced in the form of silk XX? Then the concept of subtraction XX is introduced. It also explains several problems that should be paid attention to in learning this concept, including: meixx naturally wants to know the specific occurrence process of meixx, and enters the second part, taking the formation process of sperm as the second part: the formation process of sperm.
Part II: The process of sperm formation.
First of all, use the method of reading guide to let students study with a few thinking questions. Thoughts include: "Where does sperm form? What are the cell names of different stages of sperm formation? What are synapses and tetrads? When did the' reduction' happen? " For the convenience of narration, and to explain the randomness of chromosome separation later, the chromosomes in the cell are represented by four. At the same time, in order to prevent students from being dazzled and distracted, the whole XX process appears one by one.
When talking about spermatogonia, we should not only point out that it comes from testis, but also point out that its chromosome number is the chromosome number of somatic cells. When spermatogonia form primary spermatocytes, it is emphasized that chromosomes replicate in this period, that is, in synapse, each chromosome already contains two chromatids, but at this period, chromosomes are in chromatin state, which can prevent students from mistakenly thinking that replication is carried out in tetrad period. In the tetrad period, in addition to emphasizing the concept, in order to prevent individual students from mistaking the four chromosomes in the whole cell for a tetrad, first ask: How many tetrads are there in the picture? Then flash one of the tetralogy to deepen the impression. Finally, the tetrads are summarized, and it is pointed out that the number of tetrads is the logarithm of homologous chromosomes. This way, there is a better breakthrough? Quadrupling the GNP is a teaching difficulty. In the later stage of XX, show that one homologous chromosome is separated to form two daughter cells, and then ask students to discuss whether the homologous chromosome can be separated again. After discussion, a separation diagram appeared in the later stage, indicating that chromosomes have certain independence, and which pole the homologous chromosomes move to is random, that is, different pairs of chromosomes may be freely combined. It laid a cytological foundation for studying the "separation phenomenon and the Law of Free Combination" of genetics in the future. The second XX process of meiosis is similar to that of silk XX, which is easy for students to master, but two points should be emphasized? "XX" and "equal sign" and "XX" indicate centromere XX, and sister chromatids are separated; "Equal number" means that the number of chromosomes is no longer halved. As for the process of the second reduction of XX, especially the comparison between the late XX of filariasis and the late XX of the second reduction, let the students clearly see the difference between them through pictures, that is, whether they contain homologous chromosomes, and further explain the essence of XX reduction. Then, the whole process of meiosis XX is displayed in full screen for two purposes: one is to summarize the essence of meiosis XX, and the other is to review the cell names of each XX stage on the blackboard.
2. Excellent model essay on biology lecture notes of senior one.
I. Handling of Teaching Materials According to the requirements of the new curriculum standard, the span of knowledge and the cognitive level of students, I have increased or decreased the teaching materials. For example:
Second, the choice of teaching strategies
(A use of simulation activities to enhance students' life experience.
Students have some life experience about the biological phenomena corresponding to this part of knowledge in textbooks, but they lack in-depth thinking about this experience. Therefore, thinking and cognition in the process of further strengthening this experience, so that knowledge comes from students' life experience and from students' thinking and exploration, will help to improve students' interest, fully mobilize students' existing knowledge, cultivate students' various abilities, and also help to realize the integration of theoretical knowledge and real life.
(2) Organize students to explore knowledge and form new knowledge.
Starting with students' life experience, I use cases and other forms to create situations to present problems, so that students can find, analyze and solve problems in the process of independent exploration and cooperation, and actively construct knowledge in the process of analyzing and solving problems.
In the process of guiding students to think and experience problems, students can gradually learn how to analyze and solve problems. This is not only conducive to the development of students' innovative thinking ability such as understanding, analysis, generalization and imagination, but also conducive to the improvement of students' practical ability such as expression, hands-on and cooperation, promoting students' all-round development and striving to achieve the goal of paying equal attention to teaching process and teaching results, knowledge and ability.
It is precisely because these understandings come from students' own experiences that students not only "understand" but also "believe". Recognizing these viewpoints from the heart, and then actively internalizing their emotions, attitudes and values, and integrating them into practical activities, will help to realize the unity of knowledge, practice and trust.
End:
Leaders and teachers, in this class, according to the psychological characteristics and cognitive rules of XX grade students, I adopt the teaching methods of intuitive teaching and activity inquiry, with "teachers as the leading factor, students as the main body", students' "learning" as the basis, teachers' "guidance" as the main point, and focusing on learning methods, so that students can explore independently and actively participate in the whole thinking process of knowledge formation, so as to improve themselves in a positive and happy classroom atmosphere.
My speech is over, thank you.
3. Excellent model essay on biology lecture notes of senior one.
First of all, talk about textbooks.
"The process of obtaining oxygen by human cells" is the content of XX. The main contents are: the composition of respiratory system, respiratory movement and lung ventilation, lung ventilation, gas transportation in blood, gas exchange in tissues and other knowledge points. Before learning this knowledge point, I have learned the relevant knowledge of blood circulation, mainly including the composition of respiratory system, oxygen inhalation and carbon dioxide elimination. It plays a connecting role for students to understand blood circulation, respiratory function and other circulatory systems behind.
Second, talk about learning.
The link of "lung ventilation" is the key and difficult point, which is difficult to understand. Guide students to think through their own experience and model demonstration, gradually deepen and finally solve problems naturally. The key to "lung ventilation" and "tissue gas exchange" is to let students understand the principle of gas exchange, that is, gas diffusion. I guide students to analyze the direction of gas exchange by spraying perfume, so that the problem can be solved easily.
Third, talk about teaching objectives.
1, explaining why breathing exercises achieve lung ventilation.
2. By demonstrating the model of respiratory movement, show pictures of lung ventilation and gas exchange in the tissue, and cultivate the ability of thinking in images and logic.
3. In the process of case analysis and discussion, permeate the knowledge education of safety and self-help and establish the concept of healthy life.
Fourth, talk about the difficulties in teaching.
Emphasis: the process and principle of gas exchange.
Difficulties: the process and principle of gas exchange.
V. preaching the law
The teaching methods I use are lectures, questions and answers, discussions and so on.
Sixth, talk about the teaching process.
1, introduce a new lesson
Review old knowledge, review old ones and learn new ones. The teacher leads the students to review the composition and function of the respiratory system, and on this basis, asks questions. How do people complete the respiratory function? What is the process? The process of obtaining oxygen from human cells. Constructivism advocates that teaching should start from students' existing knowledge system, and respiratory system is the cognitive basis for in-depth study of the process of oxygen acquisition by human cells. This design is conducive to guiding students to enter the learning situation smoothly and increasing the cohesion and systematization of students' knowledge.
2. New lessons.
Part I: Respiratory exercise and lung ventilation. First, make clear the knowledge of "respiratory movement and lung ventilation", organize students to feel the changes of inspiratory and expiratory thorax and make a simple summary, and then organize students to discuss the following questions in groups through the demonstration experiment of respiratory movement model:
(1) In the 1 model, the movement direction of ribs and sternum during intercostal muscle contraction is analyzed, and how the movement of bones and bones causes the change of chest volume.
(2) In Model 2, the causes of lung volume changes caused by diaphragmatic apex descent were analyzed and explained.
After discussion, teachers and students come to the conclusion that:
(1) The intercostal muscles contract, the ribs are lifted and abduction, and the sternum moves up, which increases the thoracic volume.
(2) Diaphragm contraction, diaphragmatic top descending, and longitudinal diameter of thoracic cavity lengthening, which increases the volume of thoracic cavity. Then use multimedia to show the video of lung ventilation, and combine breathing exercises to guide students to contact the outside world and exchange gas with alveoli. It is done by breathing. Because this content is easy to understand, I will combine tutoring students to read textbooks independently with guiding students to think independently, so as to achieve the purpose of autonomous learning.
The second part: lung ventilation-gas transport in blood-tissue gas exchange. Guide students to think about what happens when gas enters the lungs. So as to enter the second part of the study. First, multimedia video of gas exchange between lung and tissue is displayed, and questions are asked:
① How is the process of gas exchange in alveoli realized?
② How does blood transport oxygen and carbon dioxide? I will give students 10 minutes to guide students to discuss in groups on the basis of independent thinking. In this process, I will look around, give guidance to students and have an interactive dialogue with individual group members. When the student discussion is over, mobilize students of different levels to share the discussion results. Finally, guide students to draw the conclusion that gas exchange is realized by gas diffusion; Oxygen is transported in combination with hemoglobin in blood, while carbon dioxide is transported in plasma. Through observation and analysis, independent thinking and group discussion, we can explore new knowledge, highlight teaching priorities and cultivate students' scientific inquiry ability.
3. Consolidate and improve:
I will ask the following questions: Why does the breathing frequency and pulse increase after strenuous exercise? Organize students to use this part to explain. It is not only the process of knowledge consolidation and transfer, but also the relationship between biology and science, technology and society.
Step 4 summarize your homework
Finally, teachers and students * * * summary. In view of the differences in junior high school students' quality, I have carried out hierarchical training, which can not only enable students to master the basic knowledge, but also improve students who have spare capacity in their studies, so as to achieve the goal of being top-notch and "reducing the burden".
4. Excellent model essay on biology lecture notes of senior one.
Hello, leaders and teachers.
The theme of my speech today is "theme"
First of all, let me analyze the textbook on this topic. Before studying this topic, the students have already learned … and have a certain understanding of …, which has played a certain role in paving the way for the study of this topic. This lesson mainly includes … and …, and its study also lays the foundation for the later study of …. Therefore, it is very important to learn this lesson well. Some ... the knowledge contained in this content is an indispensable part of biology study in the future, and it is also a compulsory part of the college entrance examination in the future.
The textbook begins with … and then talks about.
Through analysis, this course has three characteristics: (1), the learning content is closely related to production and society, and the application of learning content in real life is emphasized, which reflects the connection between science and technology and society. (2) The content arrangement of this course pays attention to the cognitive characteristics of senior two students. Students have learned ... (have a certain understanding of ...) It is still difficult to learn the design of experimental steps and the handling of specific details. (3) This lesson pays attention to the requirements of the new curriculum standard for the cultivation of students' scientific inquiry ability. Consciously set up teaching activities with inquiry nature. At the same time, through reading tables, analyzing, discussing and thinking, students are guided to find answers in the process of inquiry. To cultivate students' ability of observation and analysis.
Based on the analysis and understanding of the teaching materials, I have determined the following teaching objectives from three aspects: knowledge, ability and emotion (moral education). First of all, in terms of knowledge, I think students should master and understand it. Secondly, in terms of ability, we should cultivate (cultivate) students' ability in ...; Thirdly, the emotional aspect is to guide them to cultivate what attitude, what concept and so on.
On the basis of thoroughly understanding the teaching materials, combined with the cognitive structure and outline requirements of senior two students, I made the focus and difficulty of this class: the focus of this class includes … and …, and … is their weak link, which is difficult to grasp and abstract, so the difficulty of this class is …
In order to make it clear that students can achieve the teaching objectives mentioned above, I will talk about teaching methods and learning methods again, which is the second part of this lecture.
Because biology is a subject combining theory with practice, and this book is mainly based on experiments (written on the basis of experiments), it is particularly important to cultivate students' observation ability, guide students to learn to design experiments and be able to operate them. Considering the characteristics of this course, I am going to set up situational teaching to let students actively participate in teaching activities. Specifically, I mainly use visual demonstration method: I will demonstrate by playing pictures and videos related to … to stimulate students' interest in learning and promote students' mastery of knowledge.
Activity inquiry method: acquire knowledge by creating scenes and other activities to cultivate students' self-study ability and thinking ability. Group discussion method: according to the questions raised by students, organize students to have group discussions and cultivate students' spirit of unity and cooperation.
As the saying goes, a good method can get twice the result with half the effort. There are no students who can't learn well, only those who can't. In teaching, I pay special attention to the guidance of students' learning methods and teach them to learn and use flexibly instead of memorizing. Specifically, I am going to guide them to learn this lesson by understanding memory, analyzing and inducing, exploring independently, and summarizing and reflecting.
5. Excellent model essay of biology lecture notes for senior one.
First, it is said that the textbook Cell Aging and Apoptosis is a compulsory course 1 Chapter 6, Section 3, and the requirement of the curriculum standard is to "explore the relationship between cell aging and apoptosis and human health". Students are familiar with the aging of individuals, but little is known about the aging of invisible cells. What are the manifestations of cell aging? What is the cause of cell aging? Cells go through the processes of birth, growth, maturation, reproduction, aging and death. What is the relationship between apoptosis and death? This series of problems constitute the main line of this section. Through this lesson, students can have a complete understanding of the whole life process of cells. At the same time, the study of cell decay mechanism is closely related to the development of biotechnology. Learning the knowledge of cell decay is helpful to cultivate students' scientific interest and innovative consciousness.
Second, talk about learning.
Before this class, students have learned about cell proliferation and differentiation, knowing that XX, differentiation, aging and death of cells are necessities of life, and cell aging and apoptosis are closely related to life span. Students are very interested in this, which laid the foundation for the smooth development of this class. However, students are not very clear about the relationship between individual aging and cell aging, and the difference between apoptosis and necrosis, which requires teachers to contact with real life, inspire students and correct their cognitive misunderstandings.
Third, talk about teaching objectives.
1. Summarize the characteristics of cell senescence; To explore the relationship between cell aging and apoptosis and human health; Briefly describe the difference between apoptosis and cell necrosis.
2. Combine practice to cultivate the ability to use knowledge flexibly.
3. Pay attention to the health and living conditions of the elderly; Through the discussion of the aging problem, establish a scientific concept of development.
Fourth, talk about the difficulties in teaching.
Based on the above analysis of teaching materials and learning situation and the establishment of teaching objectives, I will focus on the relationship between cell aging and apoptosis and human health. Because students' judgments on apoptosis and necrosis are easily confused, the difficulty in teaching is the difference between apoptosis and necrosis.
V. preaching the law
Use lectures and group discussions to teach and improve students' autonomous learning ability.