Living Things Need Energy

1. Living Things Need Energy Pgs. 8 -13

2. All things require energy • All living things need energy to survive. • Example: • Prairie dog eats grass and seeds to get energy. • Uses energy to grow, move, heal and reproduce. • Every living thing finds a way to gain energy and use it.

3. Energy Connection All organisms can be divided into groups based on how they obtain energy. Producers, Consumers and Decomposers are the three we will discuss.

4. Producers Organisms that use sunlight directly to make food are called producers. Using a process called photosynthesis, plants and some algae can produce their own food. Grasses are the main producers in a prairie ecosystem. Algae are the main producers in the ocean.

5. Consumers Organisms that eat producers or other organisms for energy are called consumers. A herbivore is a consumer that eats plants, like a grasshopper. A carnivore is a consumer that eats animals, like a coyote. An omnivore is a consumer that eats both plants and animals, like a bird. Scavengers are animals that feed on the bodies of dead animals, like vultures.

6. Decomposers Decomposers are organisms that get energy by breaking down the remains of dead organisms. These organisms extract the last bit of energy from dead organisms and produce simpler materials like water and CO2. They are nature’s recyclers

7. Food Chains and Food Webs A food chain represents the flow of energy through one organism to another. Not all organisms eat one kind of organism and so a more complex food web is need. A food web shows how one organism can eat several types of organisms within an ecosystem.

9. Energy Pyramids A grass plant uses most of the energy it obtains from the sun for its own life processes. Some energy is stored in tissues for later use. If a prairie dog eats some grass then it can use that energy. The prairie dog needs more energy than one blade of grass so it eats a lot of grass. Coyotes eat prairie dogs, but need more energy and must eat several to stay alive.

10. Energy Needs Each step of a food web or chain loses energy as it goes up. An energy pyramid can represent this loss of energy. The bottom of an energy pyramid has a broad base and narrow top. There is more energy available at lower levels. Energy decreases with levels because organisms use it or give it off as heat. The only energy transferred is stored in tissues of the organism.

12. Wolves and the Energy Pyramid A single species can be very important to the flow of energy, like the gray wolf. It can control the populations of other species because of its diverse diet. The gray wolves were once almost wiped out and many species, like elk, overpopulated. They are being restored to their population, but ranchers near Yellowstone are fearful they will eat their livestock.

13. Habitat and Niche A habitat is the environment in which an organism lives. The gray wolf’s habitat used to be much larger, but is now limited to areas in the northwestern United States and Canada. A niche is an organism’s way of life within an ecosystem. A niche includes its habitat, food, predators, competitors, and the abiotic factors that affect it.

14. Niche of a Gray Wolf • They are consumers(deer, moose, sheep, elk, etc). • Wolves live and hunt in packs of about six animals. • Each member has a rank. • Each pack has two leaders. • The pack teaches its young to hunt and survive. • Gray wolves are needed for the food web. • They will allow more plants to grow.