Food Chains By Mrs. Mercado
What is a food chain? • A food chain is a model that shows how is passed, in the form of food, from one organism to another. The arrows between the organisms show the direction of energy flow. Every organism needs energy in order to live. • A food chain is the sequence of who eats whom in an ecosystem. energy
The model can be represented in different ways with the arrows always pointing to the organism receiving the energy.
Energy Source • The primary source of energy is the sun. • Plants get their energy from the sun. sun hawk grass grasshopper snake Primary source of energy Producer Primary Consumer Tertiary Consumer Secondary Consumer
Producers • Green plants are called producers because they make their own food inside themselves, using water and sunlight, in a process known as photosynthesis. • The primary source of food in a food chain are green plants. They provide energy to the primary consumers known as herbivores. grass hawk sun grasshopper snake Primary source of energy Producer Primary Consumer Secondary Consumer Tertiary Consumer
Primary Consumers • The next link in the chain are the herbivores. Herbivores are the primary consumers which only eat producers (plants). • Consume means “eat.” Animals are consumers because they get their energy by eating (consuming) food provided by plants or other animals. Consumers do not make their own food. There are different levels of consumers. grasshopper hawk sun grass snake Primary source of energy Producer Secondary Consumer Primary Consumer Secondary Consumer
Levels of Consumers • Herbivores: eat only plants (producers). • Carnivores: eat meat, in other words, they eat other consumers (herbivores or carnivores). • Omnivores: eat both plants (producers) and meat (consumers).
Secondary Consumers • Carnivores are consumers who eat herbivores or other carnivores. • These consumers are also called predators because they eat other animals. The animals eaten by predators are called prey. snake hawk sun grass grasshopper Primary source of energy Producer Primary Consumer Secondary Consumer Tertiary Consumer
Tertiary Consumers predator • The predatoreats the prey therefore, the prey gets eaten by the ___________. • Here, the grasshopper is the prey of the snake, and the snake is the prey of the____________. hawk sun grass grasshopper snake Primary source of energy Producer Tertiary Consumer Primary Consumer Secondary Consumer hawk
Importance of the balancein a food chain • All the organisms in the food chain depend on each other. This relationship is called interdependence. • When one part of the food chain is altered, it affects all the parts in some way and for a long time. • When the producer is ,all the consumers are . Click to see an example of this chain reaction. reduced reduced
Food Web vs. Food Chain • While food chains follow just one path of energy, food webs follow more than one, showing multiple relationships between organisms.
Food Web FOOD WEBS show how plants and animals are connected in many ways to help them all survive.
Answer the following questions or complete the sentences. • Every organism needs _____________ to live. • Where do plants get their energy from? • The arrows point to the ______________ receiving the energy. • What is the primary source of energy? • Why are green plants called producers? • What is the primary source of food in a food chain? • What are the three levels of consumers mentioned in this presentation? • Why are the primary consumers called herbivores? • Why are the secondary and tertiary consumers called carnivores? • What do omnivores eat? • What do producers use to make their own food? • The process in which plants make their own food is known as _______________. • The secondary and tertiary consumers are also known as predators because they _______________ other _______________. • The _______________ gets eaten by the predator. • Mention the missing link in this food chain: Producer > _____________ > Carnivore • The relationship that all organisms in a food chain have is called _________________. • Food webs show ________________ relationships between __________________.
Activities Food web activity • http://www.harcourtschool.com/activity/food/food_menu.html Watch a movie about food chain. • http://www.kidsknowit.com/interactive-educational-movies/free-online-movies.php?movie=Food%20Chains Follow the activity instructions. • http://www.ngfl-cymru.org.uk/vtc/16022007/interdependence/lesson.html Select a habitat and complete the food chain. • http://www.crickweb.co.uk/assets/resources/flash.php?&file=foodchains Create a food chain • http://www.qrg.northwestern.edu/projects/marssim/simhtml/info/whats-a-herbivore.html Food puzzle • http://www.zephyrus.co.uk/foodpuzzlechain.html
Resources • http://www.myteacherpages.com/webpages/KSmith13/science.cfm?subpage=621776 • http://www.schools.utah.gov/curr/science/sciber00/8th/energy/sciber/chains.htm • http://www.arcytech.org/java/population/facts_foodchain.html • http://www.sciencebob.com/questions/q-food_chain_web.php • http://library.thinkquest.org/11353/food.htm • http://schools.bcsd.com/fremont/4th_Sci_Life_food_chains.htm • http://www.picadome.fcps.net/lab/currl/food_chain/default.htm • http://www.cas.psu.edu/DOCS/WEBCOURSE/WETLAND/WET1/identify.html • http://www.tutorvista.com/content/science/science-ii/environment/food-chain.php