FOOD CHAINS FOLLOW A SINGLE PATH AS ANIMALS EAT EACH OTHER. It is a flow of energy from one organism to the next. FOOD WEBS SHOW HOW MANY ANIMALS ARE INTERCONNECTED BY DIFFERENT PATHS. Made of individual food chains.

The source of all food is the activity of producers because only they can manufacture food from inorganic raw materials. This food feeds herbivores, called primary consumers. Carnivores that feed on herbivores are called secondary consumers. (Carnivores that feed on other carnivores are tertiary consumers.) Decomposers break down dead carnivores, herbivores, and omnivores. (Decomposer organisms and scavengers help to re-cycle essential chemicals through the food web.) PRODUCER HERBIVORE CARNIVORE

Energy is used up and lost as it moves through ecosystems. Only about 10% of the energy consumed by one level is available to the next level.

A biological relationship in which two species live in close proximity to each other and interact regularly; One or both organisms benefit. clown fish and sea anemone There are 3 basic types of symbiosis. Mutualism Commensalism Parasitism

BOTH organisms benefit. Human and dog: the dog by receiving food, shelter, and care and the human by receiving protection and loving companionship—the last two being benefits the dog also receives from the human. Bird and flower

Relationship between two different species of organisms in which one benefits, while the other member is not affected at all. Flatworms live attached to the gills of the horseshoe crab, obtaining bits of food from the crab's meals; the crab is unaffected. Barnacles and whale

Relationship between two species in which one benefits at the expense of the other. (One does not benefit.) Tapeworms, leech Malaria

Examples: predator-prey competition

A predator is an organism that eats another organism. The prey is the organism which the predator eats.

Predator? Prey? Predator? Prey?

The prey is part of the predator's environment, and the predator dies if it does not get food, so it evolves whatever is necessary in order to eat the prey: speed, stealth, camouflage (to hide while approaching the prey), a good sense of smell, sight, or hearing (to find the prey), immunity to the prey's poison, etc. Likewise, the predator is part of the prey's environment, and the prey dies if it is eaten by the predator, so it evolves whatever is necessary to avoid being eaten: speed, camouflage (to hide from the predator), a good sense of smell, sight, or hearing (to detect the predator), thorns, poison (to spray when approached or bitten), etc. Predator and prey evolve together.

keen senses camouflage

Rivalry between individuals or groups of plants and animals, for territory or resources. Competition occurs naturally between living organisms which co-exist in the same environment. Animals compete over water supplies, food, and mates.