Unit 3 Lesson 1 Earth s Support of Life

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1 Unit 3 Lesson 1 Earth s Support of Life Slide # 1

2 Unit 3 Lesson 1 Earth s Support of Life Prime Time Prep: Write down 2 things you think you know about Global Climate Change and 2 questions you have about GCC You need your book; Go get it NOW please. Then do the Prime Time Prep Slide # 2

3 Living It Up What do living things need to survive? The basic necessities of life are air, water, a source of energy, and a habitat to live in. Plate tectonics #2 Evidence Slide # 3

4 How do Earth and the sun interact to support life on Earth? During photosynthesis, plants use the sun s energy, carbon dioxide, and water to produce oxygen and glucose. Plants form the foundation of many food chains. Some animals eat plants to gain energy. Other animals eat these animals. In this way, energy from the sun is passed from plants to other organisms. Slide # 4

5 How do Earth and the sun interact to support life on Earth? Earth s rotation allows most regions of Earth to receive sunlight regularly. Regular sunlight allows plants to grow in almost all places on Earth. Earth's rotation also protects areas on Earth from temperature extremes. Slide # 5

6 How do Earth and the sun interact to support life on Earth? Earth s distance from the sun also protects it from temperature extremes. If Earth were closer to the sun, it might be like Venus, which is too hot to support life. If it were farther away, it might be like Mars, which is too cold to support life. Earth s temperatures range from below 0 C (32 F) to above 38 C (100 F), allowing life to survive in the coldest and hottest places on Earth. Slide # 6

7 How do Earth and the sun interact to support life on Earth? Which planet is too hot to support life. Which is too cold? Slide # 7

8 Summary How do Earth and the sun interact to support life on Earth? Right distance = temperature Sun s energy = photosynthesis Earth s rotation = regular light and heat Earth s tilt = allows for seasons and variations in climate around the world Slide # 8

9 Prime Time Prep: Work with your tablemate and use your notes to answer this question: How do Earth and the sun interact to support life on Earth? Slide # 9

10 How did Earth get so much water? As early Earth cooled, it released steam and other gases into the air. The steam formed clouds, water fell to Earth as rain, and Earth s oceans began. Also, icy comets and meteors impacted Earth and added water to Earth s oceans. Water, Water Everywhere Slide # 10

11 What is unique about Earth s water? Earth is unique in the solar system because it contains water in the solid, liquid, and gas states. Most of the water is in liquid form. Liquid water is essential to life because cells need liquid water in order to perform life processes. Water remains a liquid on Earth because surface temperatures generally stay above the freezing point and below the boiling point of water. Slide # 11

12 Extremophiles Extremophiles are organisms that live in extreme environments. The Antarctic has icecovered lakes and cold, dry valleys, but life can still be found there. Extremophiles live in a wide variety of places, like Yellowstone National Park's Grand Prismatic Spring (National Park Service image by James Peaco) A type of worm called a nematode survives in the cold by producing antifreeze in its cells. The presence of extremophiles on Earth makes it seem possible for life to exist in the extreme conditions on other planets. Slide # 12

13 Security Blanket How does Earth s atmosphere support life? An atmosphere is a mixture of gases that surround a planet, moon, or other space object. Some space objects have atmospheres, and some do not. It often depends on the strength of the object s gravity. Because of their size, the gravity of Earth and Venus is strong enough to hold atmospheres in place. Why do you think the gravity of Mercury and the Moon is too weak to hold atmospheres? Slide # 13

14 How does Earth s atmosphere support life? Earth s atmosphere is composed mainly of nitrogen and oxygen. It also has traces of carbon dioxide and other gases. Plants and some single-celled organisms use carbon dioxide for photosynthesis. Plants, animals, and most other organisms use oxygen to perform cell processes. Slide # 14

15 How does Earth s atmosphere support life? Earth s atmosphere was originally just hydrogen and helium. These gases, being very light, escaped into space. Volcanoes released water vapor, carbon dioxide, and ammonia into the atmosphere. Solar energy broke ammonia apart into nitrogen and hydrogen. Bacteria used carbon dioxide to perform photosynthesis, releasing oxygen into the atmosphere. Slide # 15

16 How does Earth s atmosphere support life? As the sun s radiation reaches Earth, some of it is reflected back into space, some is absorbed by atmospheric gases, and some is absorbed by Earth s surface. Earth's surface then radiates heat, which is absorbed and re-radiated by atmospheric gases through a process called the greenhouse effect. Glass lets light through, but not heat The greenhouse effect keeps Earth warmer than it would be if Earth had no atmosphere. Slide # 16

17 -- Atmosphere If all the heat stays in the atmosphere, the Earth would get too hot. Perhaps it would be better to think of the atmosphere as a blanket, and not a greenhouse? Slide # 17

18 How does Earth s atmosphere support life? Slide # 18

19 How does Earth s atmosphere support life? One type of solar radiation that can harm life is ultraviolet radiation. It can damage the genetic material in organisms. Earth has a protective ozone layer that blocks most ultraviolet radiation before it reaches Earth's surface. Each molecule of ozone is made up of three oxygen atoms. Some human-made chemicals, (CFCs) have damaged the ozone layer. Slide # 19

20 How does Earth s atmosphere support life? Slide # 20

21 How does Earth s atmosphere support life? What is the greenhouse effect? How does the ozone layer protect living organisms? Slide # 21 Layer-Healing-but

22 Key Topics: Copy this for a study guide The Sun how does the sun help make life on Earth possible? light temperature Earth s rotation and tilt Earth s Water compare amounts to other planets How did Earth get its water? How does water support life of Earth? Earth s Atmosphere compare composition to other planets What gases are in our atmosphere? How did our atmosphere form? How does our atmosphere support life on Earth? Greenhouse Effect Ozone Slide # 22 Layer-Healing-but

23 Watch this video: Bill Nye explains climate change (4 mins) Bill Nye What if all the ice melted? (6 mins) Bill Nye Climate Change Grief Nat Geo (45 mins) 6 Degrees PBS (60 mins +) Slide # 23

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25 Our ecological or carbon footprint measures how our lifestyle impacts global climate change. If you are NOT using an ipad/iphone, use this link to find out what your carbon footprint is! If you are using an ipad/iphone, do not put in your real birthday and pick Holland Elementary School, but use this link to find out what your carbon footprint is!. Slide # 25

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27 shrinking-mrdalsjökull-ice-cap,-iceland Slide # 27

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