Eight grade biological inheritance and variation teaching plan

Teaching plan is a practical teaching document for teachers to design and arrange teaching contents, teaching steps and teaching methods. In order to carry out teaching activities smoothly and effectively, according to the requirements of curriculum standards, teaching syllabus and teaching materials and the actual situation of students, class hours or topics are taken as units. The following is a sample of the teaching plan of biological inheritance and variation in the eighth grade that I have compiled for you. Welcome to read the collection.

Eight-grade biological inheritance and variation teaching plan 1 1. A brief analysis of teaching materials;

"Inheritance and variation phenomenon" is the first section of Chapter 20 "Inheritance and variation of biology" in the first volume of the eighth grade of biology published by Beijing Normal University. The textbook mainly includes three aspects:

1. By comparing the differences between individuals, students can identify biological traits and relative traits;

2. By appreciating and evaluating two cartoons of19th century, help students understand the genetic phenomenon and variation phenomenon of biology;

3. Further strengthen students' understanding of heredity and variation through after-class character investigation, thinking and practice; Help students to initially establish the concepts of heredity and variation, so as to help students understand the genetic diversity in the biological world and lay the foundation for studying the evolution of biology in the future.

Second, the analysis of learning situation:

The eighth-grade students have never studied genetics. However, they have more or less been exposed to relevant content or observed such phenomena in their daily life. It just failed to rise to the theoretical level. This laid a cognitive foundation for learning new knowledge. Moreover, the eighth-grade students already have the ability to understand, judge and reason. Teachers should fully mobilize their abilities and guide students to explore and summarize.

Third, the teaching objectives:

Knowledge goal:

1, correctly expressing the concepts of traits, relative traits, heredity and variation;

2. Be able to enumerate and distinguish biological traits, kinship traits and biological genetic variation;

3. Observe and describe the related genetic and variation phenomena.

Ability goal:

Through activities, students can master the learning method of "independence, cooperation and inquiry" and cultivate their ability to express, analyze and solve problems and practical ability in investigation, cooperation and communication.

Emotional goals:

By observing and describing the related genetic and variation phenomena, students can understand the uniqueness of individual life and cultivate their feelings of loving nature and cherishing life.

Teaching focus:

1. Understand nouns such as traits, relative traits, heredity and variation.

2, can explain and illustrate some biological phenomena in life.

Teaching difficulties:

1. Understand that relative traits refer to different manifestations of the same trait in the same organism.

2. Understand the phenomenon of heredity and variation

Teaching methods:

Autonomy, cooperation and exploration.

Teaching hours: one class hour.

Preparation before class:

Multimedia slides.

Teaching process:

First, situational introduction.

Slide show: two groups of students are familiar with the star photos. Please observe what the characters in the photos have in common in appearance, so as to introduce a new lesson: heredity and variation.

Second, new lessons.

Knowledge points 1: characteristics and relative characteristics

1, character

1) game:

Guess: Whose eyes are these?

(Introduction to Nouns-Morphological Features)

② Guess: Whose voice is this?

(Introduction to nouns-physiological characteristics)

From the above two games: character

Trait-the morphological and physiological characteristics of organisms are called traits in genetics.

2) Thinking: Does the same species have the same performance type of the same character?

3) According to the concept of characters, tell the character of grapes.

Show pictures of the same creature, show different expressions of the same feature, and get: relative features.

2. Relative characters

Relative traits-different manifestations of the same trait of the same organism.

1) Show four groups of pictures and judge whether the characters in the pictures are relative.

2) Activities: comparison and discussion of individual characteristics;

Did anyone stand with the speaker at the end of the activity? Explain whether individual traits are exactly the same?

(2) According to the results of the activity, how likely is it that two people in the world have exactly the same characteristics?

3) You can do it: Identify which of the following are relative traits. (consolidated traits and relative traits)

Knowledge point 2: heredity and variation

1, genetic

1) game: find relatives.

2) Activities: Appreciate and evaluate cartoons about character inheritance: fragments of new noses and old bricks.

Discussion:

What's the difference between the aquiline nose in New Nose and the broken leg in Old Bricks and Broken Tiles?

(2) Which cartoon expresses possible biological phenomena? Why? Please talk about the experience of the above two activities: parents and children have similarities, which shows that traits can be passed on from parents to offspring.

Heredity-The traits of children and parents are similar, which indicates that traits can be passed on from parents to offspring. This phenomenon is called heredity.

3) Show four groups of pictures related to heredity.

4) Thinking: Are the characteristics between children and parents and between individual children necessarily similar? Show three groups of interrelated pictures and let the students observe the differences between them. This leads to: variation-the existence of characteristics between children and parents and between children.

Teaching objectives of biological heredity and variation lesson plan 2 for eighth grade;

1, knowledge and skills: give examples of genetic variation and non-genetic variation, and tell the reasons for the two variations; For example, biological characteristics are not only controlled by genetic material, but also influenced by environmental factors; Experience the method of investigating biological variation, improve the ability of processing and analyzing survey data, and explain the survey results by using the knowledge learned; Examples are given to illustrate several genetic breeding methods and their applications in production.

2. Process and method: train students to sample, measure, arrange data and draw charts. Through inquiry activities, students can draw the conclusion that variation is a common phenomenon through experiments.

3. Emotional attitude and values: pay attention to the influence of high technology on human society; We can use scientific attitudes and methods to explain life phenomena.

Teaching emphases and difficulties:

1. Discussion on the variation of peanut fruit size.

2. Humans apply the principle of genetic variation to cultivate new varieties.

Class arrangement:

2 class hours

Preparation before class:

Students' preparation before class: various tools for measuring length.

Teaching equipment: (1) Two kinds of peanuts are fruity.

(2) Divide students into two groups.

(3) Using the principle of genetic variation, prepare several pictures and materials for breeding new varieties.

Teaching process design:

Teacher: There is a proverb in China, "One mother gives birth to nine children, and there are ten kinds". What can you learn from this proverb?

Student: It's about change.

Teacher: Yes, we are going to learn about biological variation today. (blackboard writing section 5 biological variation)

Teacher: What other changes do you know?

Student: For example, there are many kinds of goldfish, chrysanthemums have many colors and shapes, and dogs have many varieties.

Teacher: That's good. Of course, there are great differences between different kinds of organisms, and there are also various differences between the same species, which are all due to biological variation.

Teacher: In fact, all kinds of related words we have learned before are also produced through variation. Let's discuss the variation of a character in depth. (writing on the blackboard, exploring a variation phenomenon)

Teacher: According to the grouping before class, each group has a big peanut and a small peanut. Please choose the right tool to measure the length of each peanut. Pay attention to how to measure to minimize the error. At the same time, make records.

Student: Discuss what kind of measuring tools to use, and complete the measurement together and make records.

Teacher: Sort out your data, draw a picture, find out the maximum value, the minimum value and calculate the average value.

Teacher: What did you find by measurement?

Student: Look at similar peanuts, big and small.

Teacher: Yes, now you realize that the variation of biological characters is common. (The variation of blackboard creatures is common. )

Teacher: Why are peanuts big and small? Some big peanuts are big and some are small. What is the reason? Small peanuts are also long and short. Why?

Student: Students think and analyze the reasons.

Teacher: Some relative characters of organisms show quantitative differences (such as the fruit size of peanuts). Because any trait is the result of the interaction between the genes controlling the trait and the environment, the length of big peanuts (or small peanuts) with the same genetic composition is long or short, which is mainly caused by the environment. However, the variation caused by the environment is limited, so the fruit size of big peanuts (or small peanuts) always fluctuates within a certain range.

Student: Oh, yes, the picture I drew shows this situation. To compare the differences of these relative traits, it is necessary to compare the average values of their numbers. What's the difference between the average values you calculated?

Student: Big peanuts are big and small peanuts are small.

Teacher: In general, the average length of big peanuts should be greater than that of small peanuts. This difference is mainly caused by the difference of genetic material.

Teacher: What conclusions can you draw from the above analysis and discussion?

Student: The variation of peanut fruit length is caused by the change of environment and genetic material.

Teacher: Students, think again. What is the essential difference between these two variations?

Student: The variation caused by the change of genetic material should be heritable, and the variation caused only by the environment without the change of genetic material cannot be inherited.

Teacher: Yes. (Causes and types of variation of blackboard writing)

Teacher: After people understand the principle of genetic variation, they can use it to cultivate new varieties. Please read the examples in the book. (Book 2 on the blackboard. Human beings apply the principle of genetic variation to cultivate new varieties)

Student: Look at the picture and think about the truth.

Teacher: Due to the variation of genetic material, the genetic components of different breeds or the same breed of dairy cows can be different. Through artificial selection, cows with high milk yield (including genetic material for controlling high milk yield) can be selected. Through breeding, offspring will have various variations, and then choose to breed from them. After several generations, cows can not only maintain a high milk yield, but even have an increasing trend.

Teacher: Let's look at the cross breeding of wheat again.

Student: By crossing, combining good genes, the offspring are both high-yield and lodging-resistant.

Teacher: The students' judgment is correct. How did space pepper come into being?

Student: Look at the picture and think.

Teacher: Space pepper is a new variety cultivated under space conditions, which causes genetic changes.

Student: Is this a genetic mutation?

Teacher: Yes, gene mutation can cause biological variation. Moreover, chromosome changes can also cause variation. There are many ways to cultivate new varieties by using the principle of genetic variation. Students can consult the materials and communicate with each other after class.

Teacher: Show pictures or related video materials of "Yuan Longping and Hybrid Rice" to make students realize the greatness of China scientists and the examples of science and technology benefiting mankind.

Teaching comments:

This teaching case better embodies the spirit of student-centered and teacher-oriented teaching reform. In the teaching process, we pay attention to the integration of theory with practice, the guidance of students' learning methods, let students experience the method of investigating biological variation, improve the ability of processing and analyzing data, advocate inquiry learning, analyze data, and guide students to discuss and communicate, which has achieved good teaching results.

Teaching plan of biological inheritance and variation in grade 83 I. Teaching objectives

1, knowledge goal: correctly express traits, relative traits, heredity, variation and other phenomena;

2. Ability goal: to cultivate students' ability to analyze and read pictures through activities such as guessing riddles and enjoying cartoons; Give examples of different and relative personalities of animals, plants and people.

3. Emotion, attitude and values: By understanding the genetic and variation phenomena in the biological world, cultivate dialectical thinking ability, respect science, love nature and cherish life emotions.

Second, the focus and difficulty of teaching

1, with emphasis on distinguishing traits from relative traits; Identify and describe genetic and variation phenomena.

2. Difficulties: Understanding heredity and variation; Explain biological phenomena in the biological world.

Third, the analysis of learning situation:

Students are generally interested in biological inheritance and variation, and have some life experience in biological traits, relative traits, biological inheritance and variation, so they can easily find and discover the genetic and variation phenomena around them, but they have not yet formed theoretical knowledge and cannot make a correct explanation for related phenomena.

Fourth, the teaching process

(1) Create a situation to stimulate interest, introduce a new lesson courseware and show a set of pictures.

Teacher: Students observe them carefully, and you will notice:

1. Are they similar?

2. What are their similar characteristics?

3. What are their characteristics? Students will discuss and get into the topic smoothly. This is the phenomenon of heredity and variation that we will learn in this section.

(two) organize students to carry out a number of activities.

1: Lianliankan-Learning Biological Traitor: Many students have been to the zoo or seen many animals in books or on TV. Are you familiar with these animals? The students answered.

Teacher: The teacher has made some riddles here. Now, please read it to me. The ear of riddle is like a cattail leaf fan, the body is like a hill, and the nose is very long, which helps people to do their work. Elephant. It's good to call a horse without pulling a cart. It covers the underworld road and runs when you hear it. Zebra. An animal named deer has short antlers and a short neck. Giraffe. Shaped like a mouse, living like a monkey, crawling on branches and busy picking fruits. Squirrel.

Teacher's question: Congratulations on all your guesses. Why can you guess what animals these sentences describe?

Student: According to their morphological characteristics.

Teacher: Good. Everyone has mastered the important characteristics of animals. Pufan-like ears and a long nose are all morphological characteristics of living things. Can students talk about the morphological characteristics of other creatures?

Health: The leaves are green, the persimmons are orange, the trunk is thick ... and there is a voice.

Teacher: So voice and action are morphological features?

Health: No.

Teacher: These are the characteristics shown in life activities and the physiological characteristics of living things. For example, whether a person's color vision is normal, blood type and voice are all physiological characteristics.

Teacher: Give the concept of characteristics. The morphological and physiological characteristics of organisms are called traits in genetics.

Teacher: So what is relative trait? Please look at these pictures. Think about what is shown in the picture. Students observe the pictures and discuss the speeches.

Teacher: From the observation just now, we know that there are different types of manifestations of the same trait in organisms. Therefore, different expression types of the same trait of the same organism are called relative traits. Emphasize the same creature and the same character through examples.

Activity 2: Comparison of characteristics among individuals. Guide the students to read and identify the eight characters. Guide students to complete the comparison of individual characteristics. Complete the discussion questions in the book.

Teacher: After the inspection just now, no one stood at last. What does this mean? According to the result of this activity, what is the possibility that there are two people exactly alike in the world? (Group discussion, the representatives in the group express their opinions, and generally come to the conclusion that among the students, some of the characteristics of the same trait are the same, while others are different. The probability that all kinds of traits are identical among individuals is almost zero. ):

Activity 3: Photo Link

Teacher: in the process of self-examination of traits, what traits do you find to be the same as your parents'? What is the difference? (Ask 2~3 students to talk)

Division; Just now, the three students we heard talked about their similarities and differences with their parents, so let's play a little game: compare eyesight! The teacher shows some family photos provided by students with multimedia before class, so that everyone can guess which classmate's father or mother. Everyone is in high spirits, most of them can guess quickly, and some of them make students hesitate and guess wrong. The teacher then leads everyone to analyze why some are easy to guess right and some are wrong.

Health: Some photos are very similar to some classmates. They have a lot in common, and you can tell at a glance that they are a family. Some of them are very different, so I can't guess.

Teacher: What does this mean? Please read the first paragraph on page 100. And circle the key words. Students read quickly and master the concepts of heredity and variation. Heredity: the phenomenon that traits are passed from parents to offspring.

Variation: the phenomenon of trait differences between children and parents, and between children. )

Teacher: (Showing the concepts of heredity and variation with multimedia): Activity 4: Appreciate cartoons and answer questions in books.

Teacher: (Multimedia shows the cartoons "New Nose" and "Fragments Stripped from Old Bricks" by the famous French cartoonist Honnore du Milla. Next, let's enjoy two cartoons from the19th century.

Guide students to discuss three questions in groups:

1. What biological phenomena are expressed in the cartoon?

2. What's the difference between the aquiline nose in New Nose and the broken leg in Old Brick Fragments?

3. What kind of phenomenon is possible/impossible in comics? Why? Students discuss, and representatives of each group state their views to further deepen their understanding of the concepts of heredity and variation.

Teacher: Here are some proverbs. Let's talk about what are genetic phenomena and what are variation phenomena. Students can basically say heredity and variation.

Teacher: This shows that heredity and variation are common phenomena in biology. In natural science, the science that explores the laws of heredity and variation is genetics. We see these characteristics. Can you tell which ones are relative? The teacher played an exercise according to the video: white hair of goat and yellow hair of raccoon; The swimming of Yuanyang, the colorful feathers of Yuanyang; Black rabbit and grey rabbit. )

Teacher: How much do we know about the concepts of traits and relative traits, heredity and variation through this lesson? Can you still name the genetic and variation phenomena in the biological world? What questions do you want to know about genetics? Take out our question mark notebook and write it down. After class, we can use the internet to look up information and find ways to answer it, or you can find the answer in later study.

Homework: refer to the questionnaire on the third question of "Thinking and Practice" on page 100. You can design it yourself and investigate the characteristics of family members according to your own preferences. I suggest you present your survey results to you by statistics, charts and tables.

(C), class summary

1, correctly expressing the concepts of traits, relative traits, heredity and variation;

2. Give examples to illustrate the relative characteristics of organisms;

Verb (abbreviation for verb) assigns homework.

Sixth, teaching reflection.

Heredity and variation are common in nature. The knowledge points in this section are relatively simple. If you tell students a few concepts and give some examples, I believe students can understand. But students' enthusiasm and interest in learning may be stifled. Learning abstract contents such as "material basis of trait inheritance" and "trait inheritance has certain regularity" will produce.

Seven, blackboard design:

1 section heredity and variation phenomenon

I. People and Related People

1, Character: Morphological and physiological characteristics of organisms.

2. Relative traits: different expression types of the same trait of the same organism.

Second, the inheritance and variation of biological characters.

1, genetic phenomenon: the phenomenon that traits are passed from parents to offspring.

2. Variation phenomenon: the phenomenon that parents and children have differences in traits.

Let's call it a day.