Organisms and the Environment Chapter Four: Physical Science Connections • 4.1 Elements and Compounds • 4.2 The Compounds of Life • 4.3 Physical Variables 4.3 Ecosystems and habitats • Organisms belong to larger systems that are dependent on one another and function together. • The biosphere is Earth’s life-supporting layer of land, water, and air. 4.3 Ecosystems and habitats • An ecosystem is made up of groups of living things and their physical surroundings. 4.3 Ecosystems and habitats • A habitat is a place where a particular type of organism lives. • This fish’s habitat is the ocean. 4.3 Variables in Habitats • Individual living things are made up of many small systems that work together. • Each system has a structure (its parts) and a function (a job). What is the structure in the goldfish that functions to pump blood to it’s muscular tail? What is the function of the fish’s gills? 4.3 Land habitats • Many variables affect life on land. • Five important variables are: 1. temperature 2. precipitation 3. sunlight 4. type of soil 5. oxygen What variables can you see in these two different habitats? 4.3 Land habitats • Soil is a mixture of decayed plant and animal parts and very small rock particles. • The type of soil varies in different land habitats. 4.3 Freshwater habitats • Water covers 71% of Earth’s surface. • Less than 0.01% of Earth’s water is found in freshwater habitats on the Earth’s surface. What is the source of most of the planet’s water? 4.3 Freshwater habitats • pH is a measure of chemicals called acids and bases in water. • pH ranges from 0 to 14. • Pure water is pH 7 (neutral). 4.3 The oceans • Scientists divide the oceans into zones. 4.3 The oceans • Most life in the oceans is concentrated in zones where light can penetrate. • Life is difficult for organisms in the deep zones. • Some organisms are able to produce their own light. For what purpose do these organisms produce their own light? Investigation 3A Living Conditions • How will similar populations react to different living conditions? Chemistry Connection Chef or Scientist? • Measure accurately, stir, heat, carefully observe, and don’t stick your finger in anything. Activity What’s on your Label? • Food packages are required by law to have nutrition facts labels. • In this activity, you will study some breakfast cereal labels.