Slide # 1 Copyright © Houghton Mifflin Harcourt Publishing Company Unit 3 Lesson 1 Earth’s Support of Life

Slide # 2 Copyright © Houghton Mifflin Harcourt Publishing Company 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 # 3 Living It Up Copyright © Houghton Mifflin Harcourt Publishing Company 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. Unit 3 Lesson 1 Earth’s Support of Life Plate tectonics #2 Evidence

Slide # 4 How do Earth and the sun interact to support life on Earth? In this way, energy from the sun is passed from plants to other organisms. Copyright © Houghton Mifflin Harcourt Publishing Company Unit 3 Lesson 1 Earth’s Support of Life 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.

Slide # 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. Copyright © Houghton Mifflin Harcourt Publishing Company Unit 3 Lesson 1 Earth’s Support of Life Earth's rotation also protects areas on Earth from temperature extremes.

Slide # 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. Copyright © Houghton Mifflin Harcourt Publishing Company Unit 3 Lesson 1 Earth’s Support of Life

Slide # 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? Copyright © Houghton Mifflin Harcourt Publishing Company Unit 3 Lesson 1 Earth’s Support of Life

Slide # 8 Summary 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 How do Earth and the sun interact to support life on Earth?

Slide # 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 # 10 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. How did Earth get so much water? Copyright © Houghton Mifflin Harcourt Publishing Company Also, icy comets and meteors impacted Earth and added water to Earth’s oceans. Water, Water Everywhere

Slide # 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. Copyright © Houghton Mifflin Harcourt Publishing Company Unit 3 Lesson 1 Earth’s Support of Life 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 # 12 Unit 3 Lesson 1 Earth’s Support of Life Extremophiles Copyright © Houghton Mifflin Harcourt Publishing Company Extremophiles are organisms that live in extreme environments. The Antarctic has ice- covered lakes and cold, dry valleys, but life can still be found there. 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. Extremophiles live in a wide variety of places, like Yellowstone National Park's Grand Prismatic Spring (National Park Service image by James Peaco) by James Peaco

Slide # 13 Security Blanket Copyright © Houghton Mifflin Harcourt Publishing Company 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? Unit 3 Lesson 1 Earth’s Support of Life

Slide # 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. Copyright © Houghton Mifflin Harcourt Publishing Company Unit 3 Lesson 1 Earth’s Support of Life Plants and some single-celled organisms use carbon dioxide for photosynthesis. Plants, animals, and most other organisms use oxygen to perform cell processes.

Slide # 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. Copyright © Houghton Mifflin Harcourt Publishing Company

Slide # 16 How does Earth’s atmosphere support life? 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. Copyright © Houghton Mifflin Harcourt Publishing Company Unit 3 Lesson 1 Earth’s Support of 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.

Slide # 17 Copyright © Houghton Mifflin Harcourt Publishing Company Unit 3 Lesson 1 Earth’s Support of Life -- 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 # 18 How does Earth’s atmosphere support life? Copyright © Houghton Mifflin Harcourt Publishing Company Unit 3 Lesson 1 Earth’s Support of Life

Slide # 19 How does Earth’s atmosphere support life? 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. Copyright © Houghton Mifflin Harcourt Publishing Company Unit 3 Lesson 1 Earth’s Support of Life One type of solar radiation that can harm life is ultraviolet radiation. It can damage the genetic material in organisms.

Slide # 20 How does Earth’s atmosphere support life? Copyright © Houghton Mifflin Harcourt Publishing Company Unit 3 Lesson 1 Earth’s Support of Life

Slide # 21 How does Earth’s atmosphere support life? What is the greenhouse effect? How does the ozone layer protect living organisms? Layer-Healing-but Unit 3 Lesson 1 Earth’s Support of Life

Slide # 22 Key Topics: Copy this for a study guide Layer-Healing-but Unit 3 Lesson 1 Earth’s Support of Life 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 # 23 link

Slide # 24 Firefox