science less 2.1

Apuntes

• Subtopic: Energy Roles in an Ecosystem What are the energy roles in an ecosystem? Do you play an instrument in your school band? If so, you know that each instrument has a role in a piece of music. Similar to instruments in a band, each organism has a role in the movement of energy through its ecosystem. An organism’s energy role is determined by how it obtains food and how it interacts with other organisms. Each of the organisms in an ecosystem fills the energy role of producer, consumer, or decomposer. • Subtopic: Producers Energy enters most ecosystems as sunlight. Some organisms, like the plants and algae shown in Figure 1, and some types of bacteria, capture the energy of sunlight and store it as food energy. These organisms use the sun’s energy to turn water and carbon dioxide into food molecules in a process called photosynthesis. An organism that can make its own food is a producer. Producers are the source of all the food in an ecosystem. In a few ecosystems, producers obtain energy from a source other than sunlight. One such ecosystem is found in rocks deep beneath the ground. Certain bacteria in this ecosystem produce their own food using the energy in hydrogen s...