Science 10FEEDING RELATIONSHIPS

http://www.eduweb.com/portfolio/earthsystems/food/foodweb2.html

IMPORTANT TERMINOLOGY

SOURCE OF ENERGY FOR ALL ECOSYSTEMS IS THE SUN

Photosynthesis is the process by which plants convert energy from sun to usable energy for humans

Human survival depends on the stored energy in agricultural ecosystems

Animals that get energy from eating plants

• Possess special digestive systems for digesting all kinds of plants

• Need a lot of energy to stay alive

• May eat all day longPossess special digestive

systems for digesting all kinds of plants

Need a lot of energy to stay alive

May eat all day long

HERBIVORES

Animal that eats either other

animals or plants

Some will hunt and others will scavenge for dead matter or eggs of other animals

Generally eat only the fruits and vegetable of

fruit-bearing plants

OMNIVORES

Generally eat herbivores, but will also eat

omnivores

Require large amounts of energy in order to hunt and kill

The bigger the carnivore, the more it has to eat.

Important to the ecosystem because

they keep other species from becoming overpopulated.

CARNIVORES

DECOMPOSERS

Important terms: Trophic levels Detrivores Decomposers Pyramid of Numbers Pyramid of Biomass Pyramid of Energy Flow

SECTION 1.2 FEEDING LEVELS

First trophic level – always plants

Second trophic level – primary consumers

Third trophic level – secondary consumers

FEEDING LEVELS

Energy flows through the food chain but only about 10% of the energy is passed on from one trophic level to the next.Ex: Plant has 100kJ, caterpillar uses 10% for life processes, 90% is lost as heat or waste

Food chains are useful for describing basic feeding relationships among organisms

Pyramids illustrate different feeding relationships visual comparisons among organisms at different trophic levels

within the same pyramid and between pyramids Pyramid of Numbers Pyramid of Biomass Pyramid of Energy

ENVIRONMENTAL PYRAMIDS

Shows the numbers of organisms that are required to feed the next trophic level.

The greatest number of organisms is in the first trophic level, least number on top of the trophic level

PYRAMID OF NUMBERS

Shows the relative mass of the organisms at each trophic level

Shows the energy available in each trophic levelMore useful than pyramid of numbers because it takes into

account the size of the organism

PYRAMID OF BIOMASS

Shows the amount of nutrient energy at each trophic level (difficult to measure

Shows how the energy available at each trophic level is greatest at the bottom of the food chain and least at the top

Pyramid of energy is always upright and cannot be inverted, the other pyramids can be

PYRAMID OF ENERGY FLOW

PYRAMID OF ENERGY

http://www.vtaide.com/png/oceanchain.htm

Organisms that receive energy from dead plant and animal material

Make up majority of food chainsScavengers eat the remaining energy in large dead

organisms Ex: Vultures eat the carcasses of dead animals

DECOMPOSER FOOD CHAINS

Decomposers – types of organisms that break down cells to extract remaining energyEx: fungi and bacteria

SYMBIOSIS

Mutualism: 2 species benefit from the relationshipExample: algae lives in coral. The algae gives the coral energy and the coral gives the algae protection and carbon dioxide.

Commensalism: 1 species benefits while the other is unaffected. (shark and remora)

Parasitism: when an organism benefits at the expense of a different organism. (human and tapeworm)

http://faculty.southwest.tn.edu/rburkett/ES%20-%20%20understanding_the_environment.htm

http://www.globalchange.umich.edu/gctext/Inquiries/Inquiries_by_Unit/Unit_4.htm

REFERENCES/RESOURCES