[Origin of the theme]

By chance, I met a teenage girl in a convenience store to buy a "frozen" drink (a drink with an alcohol content of 5-8%). My curiosity prompted me to conduct a survey at the student level. It turns out that under the influence of Korean dramas, drinking has become a fashion, and some students often drink alcoholic beverages such as alcoholic beverages and beer. Therefore, how to guide students to understand alcohol correctly has become a subject that biology teaching must face. The teaching idea of "red dancing shoes that can't be taken off" came into being. I want to arouse every student's understanding of life through what they see, hear and even experience, so that they can really learn to live, communicate, create and be human.

Attachment: Questionnaire survey in student survey report (one class);

Do you drink?

Yes, 37 people, 74% No 13 people, 26%

What wine have you had?

Liquor 12 people 32% yellow rice wine 16 people 43% red wine 30 people 8 1%

Beer for 34 people, 92% champagne 14 people, 38% cocktail for 7 people 19%

Other 6 people 16% rum wine wine.

Where do you drink?

Family party 24 people 64% friends party 20 people 54%

Emotional problems 9 people 24% regardless of occasion 12 people 32%

How often do you drink wine?

Drink 1 person every day, 2 .7% twice a week for 4 people, 1 1%.

6 people take 1 6% on 23rd of the month and 25 people take 88% on 45th of the year.

Once a year 1 person 2.7%

5 the reason for drinking for the first time

Emotional problems 1 person, 2.7% provoked by friends 13 person, 35%.

Eight people who think they are grown up can drink 22%.

Curious 15 person 4 1% others 1 person 2.75

I will advise you to drink when you don't want to.

Six people insisted on not drinking 16%, and four people hesitated to drink 1 1%

Persist for a long time, but if you can't overcome it, drink 9 people, 24% and 18 people, 49%.

Do drinkers like drinking?

1 Do you like drinking? Why?

Like 16 people 43% dislike 20 people 54% average 1 person 2.7%.

Reasons for liking

10 people like the taste, 62.5% like the feeling after drinking, 5 people 3 1% and 2 people 12.5% have no reason not to drink.

Reasons for not liking it

15 For people with bitter taste, 75% drank 1 person 5%, and the other 5 people 20% felt dizzy.

Students' attitude towards drinking:

1 your attitude towards drinking, the total number of people who have drunk and have not drunk.

Bad 719%17.7% 816%

It's okay to drink less. 18 49% 8 62% 26 52%

Just have a drink of 8 22% 2 15% 10 20%

Other attitudes 411%215% 612%

2 your attitude towards classmates drinking, the total number of people who have drunk and have not drunk.

Normal 12 32% 3 23% 15 30%

Not suitable for1232% 215%1428%

It doesn't matter 13 35% 8 62% 2 1 42%

[Instructional design]

As a lesson of life education, we strive to achieve the following three points in teaching design:

1. Show the true colors of "life" and show the care of "life"

It is generally believed that there are two major crises in education today: one is the moral problems brought about by the development of science and technology; The second is the commercialization influence of global education. In the current middle school biology textbooks, people generally pay more attention to the cultivation of scientific quality and the exploration of scientific process, which affects students' way of thinking to some extent, and even forms the idea that science and technology are the only way to solve various problems, leading to the lack of humanistic spirit, thus creating a vacuum in bioethics education. There have been extreme cases such as abnormal daily behavior, unhealthy lifestyle and mentality, and even drug abuse and suicide.

Therefore, it is very necessary to show the truth of life and the care of life in biology teaching. The design of teaching content should go beyond the "scientific world", pay attention to the "real world" and care about students' daily life. As Dewey pointed out: "Schools must present the present life-that is, the real and energetic children's life. For example, the life he experienced at home, neighbor's house and playground. " Therefore, the content of biology teaching should follow the logic of students' life, take students' real life as the source and foundation, take the time and space of students' life as the clue, and choose the content design theme that students need, are interested in and have development significance, so as to make it full of the atmosphere of the times and culture.

Biology class should break through the narrow scientific world, organically integrate the scientific world with students' life world, and make biology teaching truly have vitality and practical significance.

2. Realize the infiltration and integration of scientific spirit and humanistic spirit.

Life is the unity of biology and spirituality, which requires both scientific research and humanistic interpretation. Life should be beautiful and poetic, and also rational and scientific. Scientific rationality and humanistic care are two aspects of humanistic spirit, which is the essence of science. The spirit of exploration, truth-seeking, innovation and independence shown by human beings in the face of nature is the concrete embodiment of the scientific spirit, the symbol of human beings entering a rational society and the symbol of modern civilization. Humanistic spirit is a kind of thoughts and feelings for people, a concern and understanding for people, and the ultimate concern for the subject's life. Including the overall recognition of people, respect for the unique value of life, concern for excellent national traditional culture, tolerance of different ideas, and sincere attitude towards group social life.

Life science education advocates humanistic ideal with scientific spirit and endows scientific practice with humanistic care. All scientific contents related to life should be conducive to improving students' understanding of the meaning of life and avoiding imparting pure rational knowledge. All humanistic contents related to life should have scientific and reasonable basis and should not be spread as pseudoscience. This can not only cultivate students' scientific rationality, but also improve students' humanity.

At the beginning of this topic, a new lesson, Red Dancing Shoes, was introduced with Andersen's famous fairy tale as the introduction, and teachers and students discussed the influence of alcohol on organisms together. At the same time, in teaching design, we should pay attention to the organic integration of life science and humanities, integrate scientific spirit and humanistic spirit into classroom teaching, and guide students to feel and experience profound connotation in the cognitive process. Knowledge that is external to human beings has real value only if it is internalized through perception; Only through experience can we achieve spiritual shock and emotional resonance; Only through experience can we achieve mutual understanding and heart-to-heart communication.

3. Pay attention to scientific inquiry

It is mentioned in the biology curriculum standard: "Biological science is not only numerous facts and theories, but also a process of continuous exploration." Biology education is to let students know and experience the scientific research process and learn the scientific process of scientists discovering scientific knowledge, so that students can gradually establish scientific research consciousness, subtly influence their thinking and judgment and form good habits.

Therefore, scientific inquiry should be implemented in school-based biology teaching as an effective learning method and an important learning content, and diversified inquiry activities should be designed in school-based biology teaching to create real and vivid biological situations from all aspects, so that students can learn to find, analyze and solve problems in inquiry activities, and finally every student can truly experience the fun of inquiry.

In the teaching design of this course, various forms of inquiry activities are designed, such as experimental inquiry, discussion inquiry, investigation inquiry and so on.

1) experimental exploration

Experimental inquiry is also an exploratory experiment. Biology is an intuitive experimental subject, and biological experiment is the main way for biology to guide students to carry out scientific inquiry, and its position and function are irreplaceable by any other form and method. Carrying out inquiry activities in biological experiments can change the traditional teaching materials and let students experience the disadvantages of confirmatory experiments mechanically. Students can design their own experiments and seek answers to learn actively, which can stimulate and cultivate students' interest in biological experiments, give full play to their experimental initiative, and help to form scientific concepts and methodologies for exploring the nature and changing laws of substances by using biological experimental methods.

The design of the exploratory experiment "Exploring the influence of different concentrations of alcohol on Daphnia" in this class highlights the main role of students. In the process of experiment, teachers should not only pay attention to the experimental conclusion, but also pay attention to students' enthusiasm and independent thinking, guide students to closely combine experimental observation with rational thinking, and promote the development of students' scientific inquiry ability. The experiment is organized in the form of group cooperation, in order to encourage each student to act boldly, think and express his own views, and be responsible for the progress and results of the experiment, improve the participation of all students, enable students to learn to get along with others in cooperation, and promote the development of their emotional attitudes and values.

2) Discuss and explore

The topics discussed generally appear clearly in the form of questions, which provides a fair starting point and perspective for students to explore the essence of things or phenomena. To ensure that the discussion can be fruitful, the topics discussed must be targeted and related to the students' existing experience; We should pay attention to using questions throughout the discussion process, pay attention to overall participation, advocate group cooperation, promote mutual understanding among students, let every student actively and equally participate, take the initiative to think, correctly express his personal views, and correct, improve and perfect his own views through communication with others, so as to gain new knowledge beyond personal thinking.

3) Inquiry inquiry

Before class, teachers mobilize students to carry out a survey on "Teenagers and Drinking", and encourage students to go out of the classroom, start with familiar things around them, go deep into social life practice, and obtain first-hand information and materials. With the help of personal knowledge, experience and various resources, they sort out and analyze the obtained information and materials, and summarize the survey results, so that students can not only find problems, but also put forward reasonable suggestions to solve them. In addition to in-depth practice, students are encouraged to collect information through various investigation channels such as media and internet, and students are required to sort out and analyze the collected data in the form of graphics, tables and words, and present the process and results of investigation and research in the form of short articles, posters, web pages, papers and scheme settings, so as to communicate with others openly.

In short, knowledge is no longer presented in the form of a rigid biological discipline system, but pays full attention to life and social practice, highlights the design of inquiry activities, and provides sufficient time, space and internal motivation for students' scientific inquiry.

[Teaching objectives]

1 knowledge and skills:

1) to understand the effect of different concentrations of alcohol on the heart rate of Daphnia.

2) Through learning, the system has a deeper understanding of the harm of alcohol to human organs.

2 process and method:

1) Learn the general methods of biological science inquiry, and develop students' scientific inquiry ability of asking questions, making assumptions, making plans, implementing plans, drawing conclusions, expressing and communicating.

2) Cultivate cooperative ability, practical ability and innovative ability in scientific inquiry experiments.

3 Emotional attitudes and values:

1) Participate in group discussion and study to stimulate the desire for knowledge and develop the sense of teamwork.

2) Through experimental exploration and discussion and communication between teachers and students, students can further understand the harm of the unhealthy lifestyle of alcoholism, so as to consciously develop a healthy attitude towards life and good behavior habits, and gradually form a scientific outlook on health.

[Teaching Emphasis and Difficulties]

Key points: Through exploratory experiments, we can realize the influence of alcoholism on human health and determine what kind of lifestyle we should choose to be healthy.

Difficulty: You can use the knowledge you have learned to explain the experimental phenomena and principles.

[Teaching environment and equipment] Multimedia video network system

[teaching material analysis]

The red dancing shoes that can't be taken off is an example in the limited elective course "Life Education" in Gezhi Middle School. This course chooses wine, a theme close to life practice, and tries to organically integrate life science and humanities in teaching design. Through the teaching links such as "inquiry experiment", "appreciation" and "discussion", students can have a brand-new, complete and profound perception of life in a relaxed and happy atmosphere. This course is neither pure biology nor psychology. Through hands-on experiments, students learn the general skills of engaging in biological experimental research, understand scientific concepts, cultivate students' scientific quality and spirit, and at the same time make students further understand the harm of alcoholism, so as to consciously develop a healthy attitude towards life and good behavior habits, and gradually form a scientific concept of health.

[Preparation before class]

The class conducted a small topic survey on teenagers and drinking to guide students to pay attention to this topic.

[Teaching process]

First, create situations and introduce new lessons.

In the melodious dance music, the teacher introduced a new lesson, Red Dancing Shoes, with Andersen's famous fairy tale as the introduction.

"Karen dances, she must dance-in the rain, in the sun, during the day and at night. When she was about to turn right, her shoes jumped to the left. . . . . . . Karen wants to take off her red dancing shoes, but they have reached her feet. . . . . . "

Do you still remember the famous fairy tale Red Shoes by Andersen? It tells the story that beautiful, lovely and hardworking Karen had to cut off her feet because she couldn't resist the temptation of red dancing shoes.

In fact, "red shoes" are everywhere in life. The "red shoes" of drunkards are old wine; Gamblers' "red shoes" are mahjong; Addicts' "red shoes" are drugs ... they will eventually pay a heavy price for their infatuation with "red shoes"

Teachers will vividly present the situation through multimedia animation, and the double stimulation of vision and hearing will arouse students' strong interest and motivation to explore. Therefore, it is natural to introduce the topic: "red dancing shoes that can't be taken off."

Second, situational games highlight the necessity of research.

"Before entering our topic, let's do an impromptu situational game. Please work in groups of three. Suppose you three go to a celebration. In order to enjoy themselves, two of them bought many bottles of wine and tried to persuade another student to drink it. Students according to the role they choose. Give reasons for acceptance or opposition. Now prepare for everyone 1 minute, and then I will invite a group of the most exciting simulations. "

As soon as the teacher finished speaking, the atmosphere in the classroom suddenly came alive.

It is not difficult to see the role of peer pressure in deciding whether to accept drinking from the performance of students' image. At the same time, the teacher also announced the results of the students' pre-class survey. Teenagers drink mainly because 1) peer pressure, 2) they think they are "adults", 3) they show off, 4) they escape from reality, and 5) they are fashionable and cool under the influence of the Korean Wave. Moreover, drinking has gradually become a fashion among teenagers, with the trend of expansion and younger age.

Let students pay attention to the topic of "teenagers and drinking" through students' situational games and topic surveys. The teacher further asked: "How to treat this problem correctly and objectively, and what kind of influence will alcohol have on biology?" Thus, the next link of learning activities-"exploring the influence of different concentrations of alcohol on Daphnia" is introduced.

Third, experimental exploration to understand the impact of alcohol on non-human organisms.

The teacher first briefly introduced the key words in the experiment: "Daphnia" and "alcohol". Let the students understand that Daphnia is also called "fish bug" at ordinary times. Crustaceans of Arthropoda. It is easy to collect. Because it is a lower aquatic animal, it will react with a little stimulation. The experimental phenomenon is rapid and obvious. The chemical name of alcohol is ethanol, which is a volatile and highly permeable substance. The influence of alcohol on Daphnia is various. We can use the heartbeat per minute or the survival number of Daphnia per unit time as a measure to measure the degree of Daphnia's influence.

At the same time, the teacher demonstrated in kind, usually drinking beer with alcohol content of 2-8%, alcoholic beverages with alcohol concentration as high as 58% and Erguotou (white wine). It is also proposed that "two kinds of alcohol solutions with different concentrations can be set up: 5% low concentration and 30% high concentration alcohol for experiments." Before the experiment, the teacher can put forward his own requirements: "(1) Does alcohol affect the heart rate of Daphnia? What do you think will happen in the experiment? (2) What concentration of alcohol is fatal to Daphnia? (3) Please talk about the harm of alcohol to organisms according to experimental phenomena. " And guide students to carry out inquiry activities: emphasize some details that students need to pay attention to when formulating experimental steps and specific operations in inquiry activities. The following table 1:

After understanding the learning needs, team members conduct cooperative experiments.

Fourth, with the help of video network, information interaction, exchange and discussion.

During the experiment, the whole class exchanged the observed experimental phenomena with each other through the video network demonstrator. Analyze and explain experimental phenomena. With the help of multimedia video network system, the information interaction between teachers, students and classmates is greatly mobilized, and the team spirit of team members is promoted.

Teachers also listen carefully to students' reports on the process and results of inquiry activities; Guide students to analyze and discuss experimental phenomena.

1 analysis of experimental results;

(1) What happened to the heart rate of Daphnia after dropping 5% alcohol? C

A slows down, B accelerates, C accelerates first and then decelerates, D decelerates first and then accelerates.

(2) What happened to the heart rate of Daphnia after adding 30% alcohol? C

A slows down, B accelerates, C accelerates first and then decelerates, D decelerates first and then accelerates.

It can be seen that alcohol initially acts as an exciting nerve conduction, but after exceeding a certain threshold, it turns into an inhibitory state. Even we can observe the arrhythmia of Daphnia.

2 experimental error analysis:

(1). Time measurement

(2) Some students are very tired when counting.

(3) Jumping too fast to keep up.

(4) There is an error in the average calculation.

(5) The species and sizes of Daphnia may be different.

3. (Teacher's demonstration: mortality rate is 58% and 5%)

What concentration of alcohol is fatal to Daphnia? -High alcohol concentration.

Please talk about that harm of alcohol to the body.

Through the changes of heart rate and death rate per unit time, we can see the influence of alcohol on the metabolic activity of Daphnia. (Daphnia is an invertebrate, mainly conducting electrical synapses. The influence of alcohol on electrical synapses is more significant than that of chemical synapses, and there is protein degeneration. )

In the process of interactive communication, students are prompted to think, which leads to a new question: "Daphnia in the experiment is, after all, a lower aquatic organism, while human beings are higher organisms." The human body has a certain ability to deal with alcohol, so it should not bring great harm to the human body. Moderate drinking will eliminate depression and give people spiritual pleasure. The word "moderate" is difficult to define, and everyone has different tolerance for alcohol. What happens if you unconsciously overdo it? " Then, the teacher leads the students to "explore the influence of alcohol on human body".

Fifth, watch movies and discuss the influence of alcohol on human body.

The teacher showed the effects of alcoholism on some main internal organs of human body with films, and organized the interaction among groups: each group was asked to send representatives to select the organs that were easily damaged by alcohol on the mannequin, and summarized the damage to the organs on the whiteboard in the most concise language.

At the same time, with the help of multimedia courseware, teachers and students discussed the effects of alcohol on brain, liver, excretory system, digestive system, reproductive system and skin respectively. After common induction and summary, the students learned that alcohol is a drug that can inhibit the activities of the central nervous system and belongs to inhibitors. So obviously, alcohol mainly affects the nervous system, especially the brain. Of course, the harm of alcohol to human body is various. To sum up, the short-term and long-term effects of alcohol on human body are summarized. Table 2 below:

Short-term effects, long-term effects, addiction, dependence

Alcohol depression, decreased alertness, unresponsiveness, nausea, depression, liver and brain damage, malnutrition is certain.

Table 2

Because it will produce addiction and physiological dependence, when there is no alcohol, it will produce discomfort symptoms such as headache and general pain. Alcoholics, like drug addicts, have to endure pain for a period of time.

At this point, students learned about the influence of alcohol on non-human organisms and various internal organs of the human body through study, discussion and hands-on inquiry. After uncovering the true face of alcohol, I believe that every student has his own answer in his heart. It goes without saying that alcohol should be rejected or accepted!

6. Design public service advertisements to warn teenagers to stay away from alcohol.

At the end of this class, we return to Andersen's fairy tale Red Shoes. The teacher warned that there are still many temptations in teenagers' lives, just like alcohol. Once contaminated, they will be addicted to it, such as online games, such as martial arts novels ... Karen, who is fascinated by red shoes, thinks that "nothing in the world can compare with red shoes." She only thought about red shoes and forgot to take care of the sick old woman who raised her. Even at the old woman's funeral, she kept dancing. It is inevitable that she will be forgotten in the future. Karen wasn't stuck at the beginning. She always thought that "it doesn't hurt to wear it." When she saw that the red shoes had taken control of herself, she was afraid. They were too long for her feet to take off. So we must not take any chances. Teenagers' "immunity" is not strong, so it is best to stay away from red shoes and resist temptation!

In a pleasant atmosphere, this class is coming to an end, and the teacher has assigned a small task: please give full play to your intelligence in each group and design a 30-second vivid public service advertisement after class to warn teenagers to stay away from alcohol, thus further extending classroom teaching. . . . . .

[Teaching reflection]

This lesson begins with the familiar fairy tale Red Shoes by Andersen, and introduces a new lesson, Red Dancing Shoes, to discuss the influence of alcohol on organisms. It can be said that the lead-in part is very attractive and impactful.

In the experiment of exploring the influence of alcohol on the heart rate of Daphnia, emphasizing students' cooperative learning stimulated their enthusiasm and initiative to explore the mysteries of life, made them understand the scientific truth and cultivated their experimental skills.

Appreciating the film and choosing it properly can better set off the theme and let students clearly understand the harm of alcohol to the main organs of the human body.

In the "interactive communication" link, better activate the classroom atmosphere, so that students can understand the importance and necessity of developing healthy behaviors and living habits in a democratic and happy atmosphere.

This class uses modern technology to better improve the classroom effect. In classroom design, students are the main body and teachers play a leading role. And made a good excavation in emotional attitude and values.

Disadvantages: the picture effect of Daphnia in the courseware is not good enough, so we can consider using Daphnia as a demonstration in the future. The schedule can also be appropriately compact.