how life began on the earth 公开课PPT课件

1、We live on the same planet the earth第1页/共32页1. Do you know the origin of life on earth?2. Each religion or culture has its own ideas about how life began on earth.第2页/共32页 In Chinese culture_ separates(分) the sky from the earth.Pangu 盘古skyearth第3页/共32页_ made human beings.Nuwa (女娲女娲)第4页/共32页In wester

2、n countries:_ created the world and all living things.God (上帝)第5页/共32页Do you know what a scientific idea is?Background knowledgeThe Big Bang is the term used to describe a huge explosion that scientists believe happened about 15 billions years ago. Nobody knows what caused the Big Bang. But it was t

3、he event that created our universe. The Big BangThe universe began with a Big Bang.第6页/共32页 Read the passage on P25 quickly, and match the right main idea of each paragraph. How many parts can the text be divided into?Step 1. Fast readingHow life began on the earth第7页/共32页Para.1 Para.2Para.3Para.4Pa

4、ra.5 A theory about how the universe was formedThe formation(形成） of the earthThe importance of water for lifeThe development of plants and animalsThe arrival of humans and their effects on the earthPart1: The development of the earthPart2:The development of life.第8页/共32页( 2 ) Detailed ReadingPart 1(

5、13): The development of the earth第9页/共32页Part1 (para13) The development of the earth(1) After the Big Bang, what happened?(2) What happened to the solid globe next?(3) What did the water vapour and gases were to make?(4) What appeared after the earth cooled down?(5) What did the water do?How did the

6、 earth come into being?第10页/共32页(1) After the Big Bang, what happened? a cloud of dust a violent solid ball Settled into第11页/共32页exploded with fire and rock produced water vapour and gases(2) What happened to the solid globe next?In time第12页/共32页(3) What did the water vapour and gases were to make?t

7、he earths atmosphere第13页/共32页Water appeared on its surface which is important for the beginning of life on the earth. (4) What appeared after the earth cooled down?第14页/共32页(5) What did the water do?It allowed the earth to dissolve harmful gases and acids into the oceans and seas.第15页/共32页a cloud of

8、 _ Big Banga solid _slowly combinethe earth _ downit exploded loudly with _ and _waterthe earths _dustball/globefire rockatmospherecooledHow did the earth come into being(产生）?第16页/共32页 According to the pictures, have a try to retell the development of life.第17页/共32页A cloud of energetic dust A solid

9、ballAtmosphere A world full of water4132Combine into Explode with fire and rockdissolve harmful gases Cool down 第18页/共32页Part 2 (Part 2 (45) The development of life The development of life第19页/共32页Part2 (para45) The development of lifeRead para4 carefully and make a timeline of the development of li

10、fe第20页/共32页water 1. 2. 10. 3. 4. insects (on land)5. 6. 7._8. dinosaurs (on land)9._ 11. small _ in water_ and all sorts of fishgreen plants on land _(on land and in water)forests (on land) (on land)small clever animals with _plantsshellfishamphibiansreptilesmammalshands and feet1. a timeline of the

11、 development of life第21页/共32页第22页/共32页第23页/共32页the cleverest animals第24页/共32页 The arrival of _ encouraged the _of early _. Many millions of years later _ began to appear _. Later _ appeared. Some were_. Others called _, were able to live on lands well as _. When the plants grew into forests, _appear

12、ed for the first time. After they disappeared, _became more important. They were the last group of animals different from because they _milk from within their bodies.development shellfish and all sorts of fish on land land animalsamphibians dinosaurs mammals produced small plants the first green pla

13、nts insects in the sea第25页/共32页Read pare5 carefully .find out the answer.1. What problem is caused by human being?They caused global warming.They caused global warming.第26页/共32页第27页/共32页The earth is getting warmer each year.what effects will this have? How to solve this problem?第28页/共32页Suggested Answers: The earth will be so hot that no life will exist（存在）on the earth any more. To solve this problem, people should protect the earth carefully. They must stop putting too much carbon dioxide into the air , reduce pollution, control the population and s