Energy Roles • An organism’s energy role is determined by how it obtains energy and how it interacts with other organisms. • Each of the organisms in an ecosystem fills the energy role of producer, consumer, or decomposer.
Producers • Energy enters most ecosystems as sunlight. • Some organisms, such as plants, algae, and some bacteria, capture the energy of sunlight and store it as food energy. (Through photosynthesis) • An organism that can make its own food is a producer. Energy is transferred to
Consumers • Some members of an ecosystem cannot make their own food. • An organism that obtains energy by feeding on other organisms is a consumer.
Consumers • Consumers are classified (grouped) by what they eat. • Herbivores • Carnivores • Omnivores • Scavengers
Consumers - Herbivores • Consumers that eat only plants are herbivores. • Examples: caterpillars and deer
Consumers - Carnivores • Consumers that eat only animals are carnivores. • Examples: Lions and spiders
Consumers - Omnivores • Consumers that eat both plants and animals are omnivores. • Crows, bears, and most humans are omnivores.
Animal Diet Game • http://www.sheppardsoftware.com/content/animals/kidscorner/games/animaldietgame.htm
Consumers - Scavengers • Some carnivores are scavengers. • A scavenger is a carnivore that feeds on the bodies of dead organisms. • Examples: catfish and vultures http://www.fisheriesmanagement.co.uk/catfish/catfish_introduction.htm
Decomposers • Decomposers break down wastes and dead organisms and return the raw materials to the ecosystem. • You can think of decomposers as nature’s recyclers. • Mushrooms and bacteria are common decomposers.
Food Chains and Food Webs • Energy enters most ecosystems as sunlight and is converted into food molecules by producers. • This energy is transferred to each organism that eats a producer, and then to other organisms that feed on these consumers. • The movement of energy through an ecosystem can be shown in diagrams called food chains and food webs.
Food Chains • Every living thing needs energy in order to live. Every time animals do something (run, jump) they use energy to do so. Energy is necessary for living beings to live and grow. • Animals get energy from the food they eat, and all living things get energy from food. • Plants use sunlight, water and nutrients to get energy (photosynthesis).
Food Chains • A food chain shows how each living thing gets food, and how nutrients and energy are passed from creature to creature. • Food chains begin with plant-life, and end with animal-life. Some animals eat plants, some animals eat other animals. http://www.sheppardsoftware.com/content/animals/kidscorner/foodchain/decomposers.htm
There is actually even more to this chain. • After a hawk dies, fungi (like mushrooms) and other decomposers break down the dead hawk, and turn the remains of the hawk into nutrients, which are released into the soil. • The nutrients (plus sun and water) then cause the grass to grow. • It's a full circle of life and energy!!
Food Webs • A food web consists of the many overlapping food chains in an ecosystem.
http://teacher.scholastic.com/activities/explorer/ecosystems/be_an_explorer/map/foodweb_play.htmhttp://teacher.scholastic.com/activities/explorer/ecosystems/be_an_explorer/map/foodweb_play.htm • http://www.harcourtschool.com/activity/food/food_menu.html • http://www.biologycorner.com/worksheets/foodweb.htm • http://www.vtaide.com/png/foodchains.htm
Energy Pyramids • An energy pyramid shows the amount of energy that moves from one feeding level to another in a food web. • Where is the most energy available? • Why does less energy become available at each level?
Biology The Science of Life Forward to food chains and food webs. (7:39-14)