Food Chains & Food Webs
Introduction
A food chain shows how each living thing gets its food. Some animals eat plants and some animals eat other animals.
A food web show how plants and animals are connected in many ways to help them all survive. It consists of all the food chains in a single ecosystem.
Important Vocabulary:
Autotroph- an organism that produces complex organic compounds from simple substances present in its surroundings, generally using energy from light or inorganic chemical reactions. Ex: Plants
Heterotroph- an organism deriving its nutritional requirements from complex organic substances. Ex: Dogs
Herbivore- an animal that feeds on plants. Ex: Cows
Carnivore- an animal that feeds on flesh. Ex: Tigers
Omnivore- an animal or person that eats food of both plant and animal origin. Ex: Skunk
Detritivore- an animal that feeds on dead organic material, especially plant detritus. Ex: Sea cucumbers .
A food web show how plants and animals are connected in many ways to help them all survive. It consists of all the food chains in a single ecosystem.
Important Vocabulary:
Autotroph- an organism that produces complex organic compounds from simple substances present in its surroundings, generally using energy from light or inorganic chemical reactions. Ex: Plants
Heterotroph- an organism deriving its nutritional requirements from complex organic substances. Ex: Dogs
Herbivore- an animal that feeds on plants. Ex: Cows
Carnivore- an animal that feeds on flesh. Ex: Tigers
Omnivore- an animal or person that eats food of both plant and animal origin. Ex: Skunk
Detritivore- an animal that feeds on dead organic material, especially plant detritus. Ex: Sea cucumbers .
Trophic levels of food chains
With each transition of energy, the food chain moves up levels. These levels are called trophic levels. Here is a list of the order of trophic levels.
Energy flow
Arrows in the food chain point to the organisms which are doing the eating. They represent the flow of energy through the ecosystem.
GPP & NPP
The Gross Primary Productivity is the amount of organic matter synthesized by producers in a unit area in a unit of time. GPP refers to the total productivity, including the energy used for respiration. It is dependent on the chlorophyll content.
The Net Primary Productivity is the amount of organic matter stored by producers per unit area in a unit of time. NPP refers to the net productivity that is converted to organic matter excluding the energy used for respiration. It is also dependent on chlorophyll content. |
helpful resources
Pictures Cited: http://www.peta2.com/wp-content/uploads/2013/12/rabbit-eating-grass.jpg
http://study.com/cimages/multimages/16/Trophiclevels.jpg
http://www.helsinki.fi/biosci/biopop/virtualforest/images/Kuvitus/energian_virta.jpg
http://study.com/cimages/multimages/16/Trophiclevels.jpg
http://www.helsinki.fi/biosci/biopop/virtualforest/images/Kuvitus/energian_virta.jpg