Food chain Presented by Zaib Unnisa

TOPICS UNDER DISCUSSION l Food Chain l Food Web l Types Of Tropic Levels l Ecological Pyramid

FOOD CHAIN A sequence of organisms directly dependent on one another for food.

The feeding of one organism upon another in a sequence of food transfers is known as a food chain. The chain of transfer of energy from one organism to another.

FOOD WEB An interconnection of many food chains. Topics to be discussed Photosynthesis Producers Consumers

Food web Notice that the direction the arrow points  the arrow points in the direction of the energy transfer, NOT “what ate what” Notice that the direction the arrow points  the arrow points in the direction of the energy transfer, NOT “what ate what”

PRODUCERS Organisms, such as plants, that produce their own food are called “Autotrophs”. The Autotrophs, convert inorganic compounds into organic compounds. They are called “Producers” because all of the species of the ecosystem depend on them.

Consumers All the organisms that can not make their own food and need producers are called “Heterotrophs”. In an ecosystem Heterotrophs are called “Consumers” because they depend on others. They obtain food by eating other organisms.

Primary consumers Those that feed directly from producers, i.e. organisms that eat plant or plant products are called “Primary Consumers”.

Organisms that feed on primary consumers are called “Secondary Consumers”. Those who feed on secondary consumers are “Tertiary Consumers”.

Herbivores Herbivores are animals that only eat plants. Example are grasshoppers, mice, rabbits, deer, beavers, moose, cows, sheep, goats and groundhogs.

Insects eat plants Insects eat plants. Fish, frogs, and birds eat the insects that eat the plants. This begins the food chain.

Carnivores Carnivores are animals that eat meat. Carnivores will also eat animals that eat plants.

Omnivores Omnivores will eat both plants and animals. Some animals eat both plants and meat. People are omnivores

Decomposers Absorb any dead material and break it down into simple nutrients or fertilizers Ex. – Bacteria and Mushrooms

TROPHIC LEVELS The last word that is worth mentioning in this section is “Trophic level”, which corresponds to the different levels or steps in the food chain. In other words, the producers, the consumers, and the decomposers are the main Trophic levels.

Ecological Pyramid An ecological pyramid shows the relationship between consumers and producers at different trophic levels in an ecosystem Shows the relative amounts of energy or matter contained at each trophic level The Pyramid shows which level has the most energy and the highest number of organisms