4Trophic LevelEcosystems are structured by who eats whom. A trophic level is the position that an organism occupies in a food chain- what it eats and what eats it. Every organism belongs to at least one feeding level or tropic level.
5Energy PyramidA graphical representation to show the relationship between energy and the trophic levels of a given system is an Energy Pyramid.
6Law of ThermodynamicsAs chemical energy flows through an ecosystem heat energy is lost at each trophic level. Only 10% of the chemical energy transfers and 90% is lost as heat energy.This heat energy loss is displayed in the Energy Pyramid.
9Trophic LevelProducers make their own food through photosynthesis or chemosynthesisExamples: grass, fern, cactus, flowering plant, tree, algae, some bacteria
10Trophic LevelConsumers get their energy by eating producers or other consumers.Examples: mouse, starfish, turtle, paramecium, sponge, ant, human
11Trophic LevelDecomposers break down dead organisms in an ecosystem and return the nutrients to soil, water and air. Converts bond energy from dead and decaying organisms into heat. Examples: fungus, bacteria
12What can make their own food? Producers!Autotroph auto means selftroph means nourishAn organism that produces, or makes their own food. Autotrophs are also called producers.
13Cannot make their own food Heterotroph hetero means othertroph means nourishAn organism that obtains its energy by the consumption of or decaying of other organisms.Heterotrophs are also called consumers (consumption) or decomposers (decaying).
14Types of organisms A. Consumers in an ecosystem Primary Consumer – The first consumer in a food chain/ food web and consumes a producer.Herbivores or plant eater
15Secondary Consumer – The second consumer in a food chain/food web.
16Tertiary Consumer – The third consumer in a food chain/food web.
17What it eats – niche in the food web Herbivore – An organism that eats plants, nuts, berries ie. rabbit, deerOmnivore – An organism that eats plants and animals ie. black bear, humanCarnivore – An organism that eats animals ie. wolf, hawk, whaleScavenger – An organism that feeds off of dead animals that they did not hunt or kill themselves ie. vulture
19Predator vs PreyPredator – An organism that feeds on what it hunts and kills ie. coyotePrey – An organism that is hunted and killed for food ie: mouseIs a producer prey? ______Can an organism be both prey and predator? ___
20Food Chain – A pathway in which energy flows through an ecosystem.
22Food Web – All possible pathways in which energy flows through an ecosystem.
23Energy flow… how it begins Photosynthesis – Conversion of sun’s energy to chemical energy (food). Performed by producers.6CO2 + 12H2O + Sunlight energy C6H12O6 + 6O2 + 6H20(C6H12O6 = glucose, food energy, chemical energy, potential energy - in bonds)
24Cellular Respiration – Process by which chemical energy (food) is converted to usable energy. Performed by producers, consumers and decomposers!C6H12O6 + 6O2 + 2ATP 6CO2 + 6H2O + 38ATP (usable energy for cells)
30Energy in a PondCircle the Autotrophs and draw a rectangle around the HeterotrophsDraw an arrow to all organisms that would be an energy source for decomposersLabel PH – for all organisms that perform PhotosynthesisLabel CR – for all organisms that perform Cellular RespirationLabel 1E – for the primary energy source in this ecosystemLabel 1C - primary consumers, Label 2C – secondary consumers & Label 3C- tertiary consumersList abiotic factors in pond __________________________________________________
31Energy Flow - Label in the diagram: chemical energy transfer (10%) or heat energy loss (90%)