Check Yer Head  Community Population Biosphere Organism Ecosystem Thoroughly explain the following ecological terms using complete sentences. If you can do it…you are golden! Community Population Biosphere Organism Ecosystem Biome

Energy Flow and Cycles An ECOSYSTEM is…all of the living (BIOTIC) AND non-living (ABIOTIC) things within an area…you know this. Energy moves through an ecosystem. An organism’s ENERGY ROLE is part of its NICHE. The ENERGY role can be that of a: PRODUCER CONSUMER DECOMPOSER

PRODUCERS SUNLIGHT is the primary energy source for ecosystems. Autotrophs (organisms that make their own food) are the primary producers for almost all ecosystems. Photosynthetic autotrophs are the predominant type of autotroph and they use the sun to make food. Remember…6CO2 + 6H2O 6O2 + C6H12O6 Producers are food for…CONSUMERS

CONSUMERS Consumers get energy by feeding upon other organisms. These are HETEROTROPHS…they can’t make their own food. Three Main Types: HERBIVORES: eat plant materials CARNIVORES: eat other animals…some eat dead stuff…these are SCAVENGERS OMNIVORES: eat all types of things

DECOMPOSERS These are organisms that break down waste and the remains of dead organisms. Decomposers return the raw organic materials to the soil where it is recycled back into the ecosystem. Bacteria and Fungi are two main groups of decomposers.

FOOD CHAINS: show how energy moves through an ecosystem by showing what is eating what. FOOD WEBS: are made up of many food chains. ENERGY PYRAMIDS: show how much energy is moving from one level to the next in a food web. Only about 10% of the energy at one level of a food web is transferred to the next highest level.

Because there is so much energy lost from one level to the next…the top of the food web or energy pyramid has fewer organisms.

A Typical Food Chain

A Typical Food Web Comprised of several food chains

A Typical Energy Pyramid

How the numbers work in an Energy Pyramid

Food Web..Try These… Pick an ecosystem in Yellowstone Park, and list as many abiotic and biotic factors as you can. Draw a food web within that ecosystem that includes at least four levels and six different organisms-must include the gray wolf. List all food chains and show the trophic levels and energy roles of each organism. If there is 10,000kcal of energy available at the producer level, how many kcal would be available to an apex predator? Remove one organism from your food web and explain the effect that this would have on the rest of the organisms.

CYCLES There are some major cycles that are important for biologists to understand. WATER CYCLE: a continuous process wherein water moves from the Earth’s surface to the atmosphere and back. There are four basic part to this cycle.

WATER CYCLE EVAPORATION: LIQUID water absorbs energy (heats up) and turns into a GAS (Surface to atmos.). CONDENSATION: Water vapor (GAS) in the atmosphere looses energy (cools) and turns into a liquid (clouds). PRECIPITATION: occurs when droplets of water that are formed during condensation get bigger and fall back to Earth. Transpiration: water is absorbed by plants and subsequently released back into the atmosphere through their leaves.

2. CARBON & OXYGEN CYCLES PHOTOSYSNTHESIS & RESPIRATION Producers take in carbon from CO2 and produce oxygen while consumers take in the oxygen and give off CO2 Photosynthesis (in the chloroplasts): 6CO2 + 6H2O 6O2 + C6H12O6 Cellular Respiration (in the mitochondria): 6O2 + C6H12O6 6CO2 + 6H2O + ATP (Energy) Sunlight

The Essence! Carbon is cycled (converted) from Inorganic Carbon is to Organic Carbon…and the other way around. Photosynthesis: Plants make FOOD from ENERGY Cellular Respiration: Organisms make ENERGY from FOOD.

The NITROGEN CYCLE Nitrogen is another important element for living things. Most organisms cannot get it directly from the atmosphere. Nitrogen by itself in the atmosphere is called FREE nitrogen. Nitrogen that is attached to other elements is called FIXED nitrogen…that’s the kind we need.

Organisms require nitrogen-compounds, (proteins and nucleic acids). Air is about 78% nitrogen gas (N2). That’s where most of the nitrogen hangs out. Most organisms can’t use atmospheric (free) nitrogen as is. They need it changed into nitrogen compounds. Plants need their nitrogen "fixed", which means as part of compounds such as: ammonia (NH3) urea (NH2)2CO nitrate ions (NO3−)

FYI…if you’re gonna take biology in college… There are four sub-processes involved in the Nitrogen Cycle. You don’t have to know this now, but…someday… Nitrogen Fixation: breaks N2 apart so it can form compounds. Decay: waste from life processes Nitrification: bacteria converting ammonia to nitrites and nitrites to nitrates Denitrification: bacteria converting nitrates to nitrogen gas again.

NITROGEN FIXATION This is the process that changes free nitrogen into the usable fixed kind. Bacteria in the soil and in water change the nitrogen into compounds called nitrates /NO3-(nitrobacter) and nitrites /NO2- (nitrosomonas). These can be used by other living thing to make proteins and other needed compounds. Lightning and industrial processes do this too.

When an organism dies, the nitrogen compounds return to the ecosystem and are reused. Eventually they are broken down completely (denitrification) and return to the atmosphere…and the cycle begins again…that’s why its called a cycle!