Teaching plan 1 of biological cell differentiation in senior high school in 2020
Analysis of learning situation
In junior high school, students learned knowledge about organizations, organs and systems. We have some perceptual knowledge about the examples of cell differentiation, so it is easier to understand the significance of cell differentiation for the establishment of various tissues, organs and systems. Moreover, because the content of this section involves the knowledge of individual development, students have a certain understanding of it and have a high interest in learning. As for the essence of differentiation, because students have not learned gene expression, it will be more abstract and difficult to understand. Senior high school students have acquired certain abstract thinking and comprehensive thinking ability, but their ability to concretize and visualize abstract knowledge is not enough. Therefore, teachers need to start teaching activities from common examples in students' lives.
2. Analysis of teaching content
Cell differentiation is the content of the second section of chapter 6 of the required course of biology "Molecules and Cells" published by senior high school people's education. Cell differentiation is the core content, and the study of cell totipotency and stem cells is a further expansion of cell differentiation. This section not only expands and extends the knowledge of cell structure, function and division, but also lays a foundation for studying genetic variation, and is also the theoretical basis of cloning technology and embryo engineering. So it is necessary to learn this lesson well.
3. Teaching objectives
Knowledge Objective: (1) Explain the concept and biological significance of cell differentiation.
(2) Illustrate the concept of cell totipotency and its application in scientific practice with examples.
Ability goal: (1) Cultivate students' thinking ability of analysis and induction, and improve students' scientific inquiry and biological literacy.
(2) By collecting information about stem cells, students can learn to identify, select, use and share information.
Emotional attitude and values: (1) Through the analysis of cell differentiation and totipotency, gradually establish a scientific world outlook.
(2) By collecting data about stem cells, guide students to pay attention to human health problems and stimulate their sense of social responsibility.
4. Teaching emphases and difficulties
Teaching emphasis: the concept and significance of cell differentiation; The concept of cell totipotency.
Teaching difficulty: the concept of cell totipotency and its examples.
Preparation before class
(1) Collect different cells of human body; Looking for videos of embryonic development,
(2) Making multimedia courseware.
6. Class arrangement: one class.
7. Teaching process
Teaching content (steps) Teacher's organization and guidance of student activities (preset) Introduction of teaching intention
Play a video of the development of human embryos.
Set doubts
Repeat the video and ask why a cell can develop into so many different cells. Clarify the content of this lesson, introduce a new lesson "cell differentiation" to clarify what you have learned, so that your learning motivation can be stimulated and you will be interested in the new lesson. Stimulate students' interest in learning. New lesson
1 cell differentiation
The concept of (1) cell differentiation
Show a group of pictures of different cells in the human body. And make a brief introduction, highlighting its morphological structure and functional differences.
● Question: Contact the video of fertilized egg development in class and think about where these different cells come from.
● The teacher guided and summarized the concept of cell differentiation.
● Question: Although the morphological structure and function are different after differentiation, what is the same in each cell? Cells of the same organism (such as humans)
It is considered that these cells with different morphological structures and functions are developed from the same cell.
● Summarize the general meaning of cell differentiation under the guidance of the teacher.
● Genetic material
● Show pictures with vivid images.
● Cultivate students' ability to analyze and summarize.
● Pave the way for explaining the essence of cell differentiation. (2) The essence of cell differentiation
● Question: Why do all cells of the same organism contain the same genetic material, but there are great differences in morphology, structure and function?
● After the college entrance examination, the schools in front of students with the same scores are all the same. Why do you end up in different schools?
● Follow-up: Now let's think about why all cells of the same organism contain the same genetic material, but their shapes, structures and functions are quite different.
● Think positively.
● Entering different schools after the college entrance examination is because the ideals are different, so the choices are different.
● The result of gene selective expression ● Derived the content of cell differentiation essence.
● Analogize the essence of cell differentiation.
Cultivating students' analogical reasoning ability is helpful to understand the essence of cell differentiation. (3) the significance of cell differentiation
Combined with life examples, the factory analogy organism, division of labor analogy cell differentiation.
Students, there are different people doing different things in the factory (compared with the factory that produces drinks). Some people prepare drinks and some people are responsible for bottling, so that the factory can run smoothly and the drinks can be produced smoothly. Each individual is like a factory, cells are like workshops in the factory, and cell differentiation is like the division of labor in the factory.
● If everyone is in charge of bottling, can the factory still operate and can drinks still be produced?
Teaching plan 2 of biological cell differentiation in senior high school in 2020
Teaching preparation
1. Teaching objectives
1, knowledge target:
(1) Describe the concept of cell differentiation and its significance in individual development.
(2) Illustrate the role of cell totipotency in production practice and scientific research, and tell the essence of cell totipotency and the difference between plant cells and animal cells, so as to distinguish the size of specific cell totipotency.
(3) By observing the external morphology of human body, let students describe the characteristics of cell aging;
(4) Distinguish the relationship between cell senescence and individual senescence;
(5) Grasp the significance of apoptosis;
(6) Understand the difference between apoptosis and necrosis.
2, ability goal:
(1) Under the guidance of teachers, teachers and students explore together, let students learn to learn, and cultivate their analytical and inductive thinking ability and autonomous learning ability.
(2) Explore the characteristics of cell differentiation and the concept of cell totipotency, and cultivate students' scientific inquiry methods and biological literacy.
(3) By asking questions about the displayed examples, cultivate students' ability to extract useful information and express it in language.
3. Emotions, attitudes and values:
(1) Through learning, let students understand the movement of life and the influence of internal and external factors on the process of life.
(2) to guide students to pay attention to the major social problems and human health problems facing the world today, to stimulate the sense of social responsibility and mission, and to stimulate students' good feelings of caring for life.
2. Teaching emphases/difficulties
1, teaching focus
(1) The concept and significance of cell differentiation and the concept of cell totipotency.
(2) Understand the relationship between individual aging and cell aging;
(3) Understand the characteristics of cell senescence; Understand the concept of apoptosis.
2. Teaching difficulties
(1) The concept of cell differentiation, cell totipotency, the concept and examples of stem cells.
(2) The difference between cell senescence and cell necrosis.
3. Teaching tools
Teaching courseware
label
teaching process
Teaching process design
raise a question
What is the starting point of personal development?
In the process of fertilized eggs developing into individuals, the number of cells changes from less to more. What kind of cell proliferation pattern does it depend on?
If the number of cells is increased simply by cell division, will an independent biological individual be formed?
Student discussion
Students are exposed to knowledge about cell proliferation. The starting point of individual development is the fertilized egg. In the process of fertilized eggs developing into individuals, the number of cells changes from less to more, depending on mitosis, but if only cells divide, independent organisms cannot be formed. To form a biological individual, it is necessary to introduce "first cell differentiation" through cell differentiation.
Teacher guidance
The formation of individuals not only increases the number of cells through cell division, but also goes through the process of cell differentiation. So what is cell differentiation?
Student answers
In the process of individual development, the offspring produced by the proliferation of one or a class of cells have stable differences in morphology, structure and physiological functions.
Teacher guidance
So when did cell differentiation happen? What are the characteristics? (Guide students to read the textbook page 1 13 to summarize the characteristics and significance of cell differentiation)
Students discuss the teacher's problems by induction.
Cell differentiation is a very common life phenomenon in biology (universality); Cell differentiation occurs in the whole life of an organism, but it is the most vigorous and frequent (lasting) in the process of embryonic development; Differentiated cells will always remain differentiated and will not become other cells (stability); Hematopoietic stem cells will differentiate into red blood cells, eventually aging and dying, and will not form hematopoietic stem cells again (irreversibility), and the genetic material will not change during differentiation (invariance of genetic material).
So what is the significance of cell differentiation to the growth and development of organisms?
Cell differentiation makes cells in multicellular organisms tend to be specialized, which is beneficial to improve the efficiency of various physiological functions. It is the foundation of personal development.
Teacher guidance
Now we know that the formation of individuals requires both cell division and cell differentiation.
Since every cell of the same individual is produced by the mitosis of fertilized eggs, and cell differentiation makes stable differences between cells, are these differences caused by changes in the genetic material of cells?
Students discuss the teacher's problems by induction.
Cell mitosis can ensure that each daughter cell obtains the same chromosome as the mother cell and has the same genetic information, and the genetic material has not changed. The genetic essence of cell differentiation is the result of gene selective expression. The teacher gave concrete examples about cell differentiation.
Red blood cells synthesize hemoglobin, while myocardial cells synthesize actin and myosin-the result of gene selective expression-cell differentiation.
Students think, read and analyze.
? Fig. 7- 1 shows the flow chart of plant tissue culture.
Student discussion
What is the concept of cell totipotency through the analysis of plant tissue culture experiments? Why are cells omnipotent?
Student discussion
Cell totipotency means that highly differentiated plant cells still have the potential to develop into complete individuals, which we call cell totipotency. Highly differentiated plant cells contain all the genes that maintain the inheritance of this species, which is the fundamental reason why cells are totipotent.
Teacher guidance
Through the analysis of plant tissue culture experiments, it is concluded that highly differentiated plant cells still have the potential to develop into complete individuals, which we call totipotency. So why are cells totipotent?
Teacher guidance
Can highly differentiated plant cells lose genes due to differentiation? (no)
Highly differentiated plant cells contain all the genes that maintain the inheritance of this species, which is the fundamental reason why cells are totipotent.
raise a question
According to the above logic, highly differentiated animal cells should also be totipotent and can develop into complete individuals. But is this the case? So far, people have not successfully cultivated a differentiated animal cell into a new individual. Then some students may ask questions. What about cloned sheep?
Explain the process diagram of animal cloning-"Dolly".
Student discussion
The conclusion is that the totipotency of well-differentiated animal cells is limited, while the nucleus of well-differentiated animal cells is totipotency.
Which sheep is the most similar to cloned sheep? The basis of speculation? Provide the nucleus, which contains a whole set of genetic material of this species. Therefore, although the totipotency of highly differentiated animal cells is limited, the nucleus is totipotent.
Teacher guidance
From the above experiments, we know that the nucleus of animal cells is totipotent. Since the nucleus of each cell still has all the genetic material, why can't highly differentiated animal cells directly develop into complete individuals? What is the totipotency of animal cells? Ask the students to compare plant cells with animal cells. Totipotency of fertilized eggs, egg cells and somatic cells.
Student discussion
Highly differentiated animal cells have almost no totipotency. The totipotency of highly differentiated plant cells is greater than that of highly differentiated animal cells; The fertilized egg has the greatest totipotency; The conclusion is that the lower the degree of cell differentiation, the higher the totipotency.
Teacher guidance
So neither animals nor humans have cells that can divide and differentiate? (Explain the process of cell differentiation)
Students discuss, and teachers and students * * * cooperate to summarize.
There are still a few cells in animals and humans that have the ability to divide and differentiate-stem cells.
Students think.
Fig. 7-3 is a schematic diagram of the process of stem cells differentiating into various blood cells. Discuss the classification of stem cells
Stem cells can be divided into totipotent stem cells, pluripotent stem cells and pluripotent stem cells according to their differentiation potential. It is concluded that the cells that divide in the early stage of fertilized eggs are totipotent. With the division and differentiation of cells, the development potential is gradually limited, from totipotent stem cells to pluripotent stem cells, to pluripotent stem cells, and finally to cells at the end of differentiation.
The teacher tells?
Written information about leukemia and bone marrow transplantation.
raise a question
1, please talk about your understanding of leukemia.
2. Donate an appropriate amount of hematopoietic stem cells, why not harm the health of donors?
3. Why can bone marrow transplantation treat human leukemia?
Student discussion
1. There are a large number of abnormal white blood cells in the blood of leukemia patients, while the normal blood cells are obviously reduced.
2. Hematopoietic stem cells of healthy people will constantly produce new blood cells.
3. There are hematopoietic stem cells in bone marrow, which can produce various blood cells (transition).
Students, we are lucky because we are healthy. What can we do for leukemia patients? Students express their opinions, and the teacher said, ah, as long as everyone gives a little love, the world will become a beautiful world.
raise a question
1. Characteristics of human aging: white hair, wrinkles, senile plaques, deafness, dizziness, slow movement, memory loss, etc.
There will still be young cells in the elderly. For example, spermatogonia can still proliferate to produce sperm, and hematopoietic stem cells can proliferate to produce various types of blood cells throughout their lives; Young people also have cell aging, such as skin epidermal cells aging into stratum corneum cells, and finally cells apoptosis and shedding.
Teaching plan 3 of biological cell differentiation in senior high school in 2020
Analysis of learning situation
The teaching object of this class is senior one students. In junior high school, students learned knowledge about organizations, organs and systems. We have some perceptual knowledge about the examples of cell differentiation, so as to better understand the significance of cell differentiation for the establishment of various tissues, organs and systems. And because this section involves personal development and other knowledge, students have a certain understanding of this and have a high interest in learning.
In this unit, students should have learned the content of "cell proliferation". Therefore, we have a systematic understanding of individual development. As for the essence of differentiation, because students have not learned gene expression, it will be more abstract and difficult to understand; Plant tissue culture, animal cloning technology and other knowledge. Students have neither intuitive impression nor relevant information reserves. Therefore, cultivating students' ability to actively construct concepts, collect and process information and connect with practice is the basis of learning this section well.
Through the study in this section, if students master the knowledge about cell differentiation, it will lay a foundation for studying cell canceration and the expression of genetic part in the future.
Students may have a pre-scientific concept: "The genetic material of differentiated cells will change, and differentiated cells can no longer differentiate into other cells."
3. Analysis of teaching content
, the knowledge structure of this lesson:
"Cell differentiation" is the content of the second section of the sixth chapter of the new curriculum standard 1, which consists of two parts: cell differentiation and its significance and cell totipotency. Cell differentiation is an important content in the course of cell life, an important physiological process and phenomenon in individual development, and the foundation and core of multicellular biological development. Cell differentiation is a lasting and stable change based on cell division. Differentiated cells have totipotency under certain conditions, and the specific application of animal nuclear totipotency-cloning technology is a hot spot in life science today. This section not only expands and extends the knowledge of cell structure, function and division, but also lays the foundation for learning heredity and variation. At the same time, this part of knowledge is closely related to many new hot issues of scientific and technological progress, so it is very important to understand or solve some practical problems with practice, and it will also stimulate students' enthusiasm for understanding science.
The concept of cell differentiation is so profound that it is difficult for students to understand it. It can be demonstrated by providing sufficient perceptual materials: image information and multimedia courseware to demonstrate the individual development process of animals and plants; Help students understand that cells similar to each other in early embryos develop into cells with different shapes, structures and functions after division and differentiation. So as to realize the importance of cell differentiation. After students understand the significance of cell differentiation, they can be guided to go deep into the essence from the phenomenon and explore whether the stability difference caused by cell differentiation is caused by the change of genetic material. How to prove your point of view in a scientific way? Cultivate students' scientific research methods and innovative spirit. Finally, the significance of cell differentiation is summarized by analogy.
Cell totipotency is a difficult point in teaching. Using multimedia experiments of totipotency of animal and plant cells and students' examples can deepen understanding.
The biological concept of this lesson
(1) In the process of individual development, the offspring produced by the proliferation of one or a class of cells have stable differences in morphological structure and physiological functions, which is called cell differentiation. ② Under certain conditions, highly differentiated cells can differentiate into other cells like early embryonic cells.
Stimulate and maintain learning motivation
Asking students to collect information about leukemia, plant tissue culture and cloned animals before class can stimulate students' interest in this part, and also let them know something about it, so that they will not feel strange when studying.
At the beginning of the class, let students report the collected results, which can arouse students' interest, enhance their sense of accomplishment and build their confidence in learning this part of knowledge.
Teaching objectives
Through the study of this course, students should be able to achieve the following goals.
(1), knowledge target
① Describe the concept of cell differentiation and its significance in individual development.
② Illustrate the role of cell totipotency in production practice and scientific research with examples, and tell the essence of cell totipotency and the difference between plant cells and animal cells, so as to distinguish the size of specific cell totipotency.
(2), ability goal
(1) Under the guidance of teachers, teachers and students explore together, so that students can learn to learn and cultivate their analytical and inductive thinking ability and autonomous learning ability.
② Explore the characteristics of cell differentiation and the concept of cell totipotency, and cultivate students' scientific inquiry methods and biological literacy.
(3), emotional attitudes and values.
① Through the study of cell differentiation, establish a dialectical materialist view of nature and gradually establish a scientific world outlook.
② Through the study of cell totipotency, collect and analyze the information about the progress of stem cell research, and cultivate and pay attention to the development of biological science, life and health, social hotspots and other issues.
6. Teaching emphases and difficulties
Teaching focus
The concept and significance of (1) cell differentiation
(2) the concept of cell totipotency
(3) the relationship between cell differentiation and cell division
Teaching difficulties
The concept of (1) cell differentiation
(2) The concept and examples of cell totipotency.
Preparation before class
Students should consult the information about cell differentiation and cell totipotency before class to improve their interest in learning.
Teachers make ppt, prepare video pictures about cell differentiation and cell totipotency and insert ppt, and consult a lot of relevant materials to enrich their knowledge.
Class arrangement
One class hour (10 minute)
teaching process
Time teaching
Teachers' Teaching Behavior and Teaching Strategies of Students' Behavior Teaching Skills in the 1940s
1940s
70 s
60 s
120S
20S
150S
1940s
60' s review
lead into/introduce
explain
abstract
practise
All living things go through the life course of birth, growth, maturity, reproduction, aging and finally death. So do living cells. Last class, we learned about the division of cells and learned that organisms are developed from fertilized eggs. Does the increase of cell number mainly depend on meiosis? Please _ students answer. (Mitosis) What is the significance of mitosis? Increasing the number of cells maintains the stability of genetic traits between parents and offspring, which is of great significance to the inheritance of organisms.
There are more than 200 different kinds of cells in the human body, and all the cells that make up the human body are produced by mitosis of a fertilized egg. However, the genetic information between the parent cells and the offspring cells produced by mitosis is the same. How did a fertilized egg form so many different cells? Explain what changes need to be made besides cell division. Next, let's discuss this problem together.
One,
The concept of cell differentiation
1. Multicellular organisms form two cells, four cells and eight cells from a fertilized egg through mitosis, and finally produce various cells, such as red blood cells, muscle cells, nerve cells and epithelial cells, which perform different functions respectively. This process is cell differentiation.
2. The concept of cell differentiation: In the process of individual development, the offspring produced by the increment of one or a kind of cells have stable differences in morphology, structure and physiological functions, which is called cell differentiation.
3. Comparison between cell differentiation and cell division: the difference is that cell division increases the number of cells, but the morphological structure and function remain unchanged; Cell differentiation increases cell types and changes morphological structure and function. Similarity: Genetic information remains unchanged. Contact: * * Complete the growth and development process of biological individuals.
Second,
Characteristics of cell differentiation:
Universality: Cell differentiation is a universal life phenomenon in biology. Cell differentiation occurs not only in animal cells, but also in plant cells.
Persistence: Cell differentiation runs through the whole life process of an organism and reaches its maximum in the embryonic stage.
Stability: Epithelial cells cultured in vitro always remain epithelial cells and will not become other types of cells.
Irreversibility: In the process of cell differentiation, if A cells differentiate into B cells, it generally does not show that B cells differentiate in the opposite direction to form A cells.
Third,
The essence of cell differentiation:
What is the most abundant organic substance in the molecules that make up cells? (protein) protein is the main undertaker of life activities. How is the synthesis of protein controlled? (DNA) DNA consists of four deoxynucleotides. Deoxynucleotide sequences represent genetic information. Is the genetic information the same in different cells of the same individual? (Same, all from the same fertilized egg) Why do the same genetic information synthesize different protein? This involves the selective expression of genes.
Suppose a cell contains five genes, but only expresses the genetic information of gene A and gene C. The cell synthesizes hemoglobin that transports oxygen, and the cell develops into red blood cells. Similarly, if BC gene is expressed, cells will differentiate into epithelial cells; If the CE gene is expressed, the cells will differentiate into nerve cells.
Just try it. Can you explain these phenomena? PPT seventh)
Both red blood cells and muscle cells contain hemoglobin genes and actin genes, but in red blood cells, genes related to hemoglobin synthesis are active, while genes related to actin synthesis are closed. In muscle cells, the opposite is true.
Fourth,
The result of cell differentiation; Different kinds of protein were produced, which finally changed the morphology, structure and physiological function of cells.
Five,
The significance of cell differentiation:
Question: What will happen if all kinds of cells in multicellular organisms have the same morphological structure and function?
Every cell of an organism has no functional differentiation, so the efficiency of life activities is low and the metabolic rate is slow.
Therefore, the formation of various tissues and organs through cell differentiation is the basis of individual development. Make the cells in multicellular organisms tend to be specialized. It is beneficial to improve the efficiency of various physiological functions.
Think about it; Will the genetic material of highly differentiated cells change? Can it differentiate again?
The genetic material of highly differentiated cells will not change. But it will not differentiate again in individuals, and the differentiated cells are permanent and irreversible, so it will not differentiate again. However, in vitro cells can differentiate into other cells again like early embryonic cells under certain conditions. This is the totipotency of cells, which will be studied in the next class.
From the analysis of individual development process, the increase of cell number by cell division belongs to quantitative change in the development process, and the diversification of cell types by cell differentiation belongs to qualitative change in the development process. Cell division and differentiation run through the whole process of individual development, but at different stages, different cells have different expression levels. Individual development is realized on the basis of cell division and differentiation.
1, the main differences between cell differentiation and cell proliferation are: (d)
A. the number of cells increased;
B. the cell morphology and structure are the same;
C. The physiological functions of cells are similar;
D. the process of stability differences in morphology, structure and physiological functions of the offspring of the same cell;
2. The cell with differentiation ability is (C)
A. Cardiomyocytes B. Nerve cells
C. Early embryonic cells
3. The following statement about cell differentiation is wrong (C)
A. Cell differentiation is closely related to biological development;
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