Organisms represented in Food Chains / Food Webs.

Food Chains A food chain shows how each living thing gets its food. Each link in this chain is food for the next link. A food chain always starts with plant life and ends with an animal.

Producers: (autotrophs) Organisms that can make their own food by photosynthesis. (e.g. green plants synthesis sugars from CO2 and H2O)

Heterotrophs Consumers: (Heterotrophs) Organisms who must eat other organisms (dead or alive) to obtain their energy.

Primary Consumers Herbivores are plant eaters. They are also called primary consumers.

Carnivores Carnivores: Meat Eaters Carnivores that eat herbivores are called: Secondary Consumers 2o Carnivores that eat other carnivores are called Tertiary 3o and Quaternary 4o consumers. Top Carnivore: Meat eater at the top of the food chain. Not often hunted by other organisms.

Omnivore

Scavenger Prey on dead organisms

Decomposers Organisms that clean up the environment. They secrete digestive enzymes onto dead organism matter and absorb the digested material. (e.g. fungi, bacteria)

TROPHIC LEVELS: The different feeding level of organisms in an ecosystem are called tropic levels. Producers make the first tropic level in all ecosystem. In a healthy ecosystem there are lots of producers, some herbivores and few carnivores.

Lets make a trophic level pyramid for the following food chain

Consider this food chain Let’s answer questions 3 a,b,c.

Energy flows in a one way direction in an ecosystem. Buckwheat ---> Gopher ---> Gopher snake ----> Red Tailed Kite

FOOD WEBS Organisms must rely on more than one food source to meet their daily energy requirement. A food web is a series of related food chains displaying the movement of energy and matter through an ecosystem.

Consider the following food web Answer questions 4 a-g, 5, 6

Energy Energy is lost at each level of the food chain Only 10 % of energy gets passed on. 90% of the energy consumed is used by the organism for day to day functions such as: 1. Growing 2. Moving 3. Body Heat 4. Reproducing 5. Breathing etc…