How Life Began on the Earth

Period 1

Unit 4 Astronomy:Unit 4 Astronomy:

the science of the starsthe science of the stars

AstronomyAstronomy is the scientific study of the universe and the heaven bodies (such as the sun, the moon, and stars), gas, and dust within it.

astronomerastronomer

Check your knowledge

1. Now we know________ goes around the the earth. The earth goes around _______.

2. There are _____ planets in the solar system, including the earth.

3. The solar system is just a small part of the ________.

The Solar systemThe Solar system

the moon

the sun

eight

Milky Way galaxy / universe

The Solar systemThe Solar system • eight planets• many comets• other objects

How did the earth come into being?

How did the earth come into being?Chinese tale: Pangu created the world

Bible: God created the universe

Science: The Big Bang Scientists believe that around 15 billion years ago, a huge explosion happened, creating our universe.

The Big BangThe Big Bang

A cloud of dust

Combine into a solid ball

Explode…with fire & rock

(produce H2O, CO2,O2, N2, other gases)

atmosphereCool down

water appeared dissolve harmful gases into …

Life began

Life developed

What are the special qualities of the earth?

There is water on the earth. How did water come into being on the earth?

The explosion of the earth produced water vapor, which turned into water when the earth cooled down.

Water is the headspring of life.Water is the headspring of life.

The development of life

1________________ 2____________________

3________________4__________5__________

6_________7__________8__________9__________

small plants in water shellfish and all sorts of fish

green plants on land insects (on land)amphibians (on land and in water)

forestsreptiles (on land)dinosaurs (on land)mammals (on land)

plants

animals

Good morning, I am …. I’m greatly

honored to be here to give you a speech

about the development of life. …

• After the “Big Bang” came a _____ of energetic dust. Dust combined into a ball, moving ______ the sun. The earth became violent. Then it ______ loudly. In time, the water vapor was produced, making the earth’s atmosphere ______ down. Water then appeared on the _____. Water disappeared from other planets. But it stayed on _____.

Finish the summary according to the text: cloud

around exploded

cool surface

earth

• Then ________ grew. They multiplied and filled the oceans and seas with _____. Many millions of years later the first _________ began to appear on land. When the plants grew to forest, _____ appeared for the first time. They produced young generally by __________. When dinosaurs disappeared, ________ became more important.

• Millions of years later, small _____ animals were found to be living on the ______, in the sea. They spread all over the earth, moving ______ the earth, putting too much carbon dioxide into the atmosphere which _____ heat form escaping from earth into space. In the end the earth may become too hot to live ___.

clever land

around

prevents

upon

small plants oxyge

ngreen plants reptile

slaying eggsmammals

Assignment Think about how to protect the earth and make it a better place to live on? (write a rep

ort in a group of four, we will discuss it next class)

________made it possible for life to begin to develop.

Water

Plants encouraged the development of _____________________________.early shellfish and all sorts of fish

Later _____________ appeared.

land animals insects

amphibians

When plants grew into forests, ______ appeared for the first time.reptiles

Some huge animals, called _________, developed.Some huge animals, called _________, developed.

dinosaurs

When dinosaurs disappeared, _________ became more important.

mammals

How to protect the earth and

make it a better place to live on?

What damage are we human beings doing to the earth?

The development of life on the earth:

the Big Bang, a cloud of dust, a solid ball, explode, water vapour, water appeared

small plants in water, shellfish and all sort of fish, green plants on land, insects, amphibians, forest, reptiles, dinosaurs, mammals

later, many millions of years later, after a long time, …

appear, develop, begin to live on the earth, come into being, …

Further discussion: (choose one of the topics):

Do you think the earth may become too hot for the lives on it? why?

How should we treat the earth?

Do you think the problem of global warming can be solved? If so, what should we do?

Homework (choose one of them):

1.Write a passage about the development of life on earth.

2.Find out one or two different ideas about the beginning of life on the earth.