Ecology
a relationship in which two different organisms live in close association with each other
Symbiosis
a linear model showing how energy flows from one organism to the next single path.
Food Chain
Atmospheric nitrogen gas is converted into ammonia or ammonium by symbiotic bacteria (e.g., Rhizobium in the roots of legumes) or through physical processes like lightning.
Nitrogen Fixation
Plants, algae, and cyanobacteria absorb CO2 from the atmosphere. They use sunlight to convert it into glucose, which builds plant tissues.
Photosynthesis
organisms that create their own food using light, water, carbon dioxide, or other chemicals.
Autotrophs
Both organisms benefit from the relationship
Mutualism
multiple interconnected food chains in an ecosystem
Food Web
Soil bacteria oxidize the ammonia into nitrites, and then further into nitrates, which is the form plants can easily absorb through their roots.
Nitrification
Animals (and humans) eat these plants, transferring the carbon compounds through the food chain to build their own cells.Respiration: All living things (plants and animals) constantly break down glucose for energy, releasing CO2 back into the atmosphere as a byproduct.
Consumption
an organism that cannot synthesize its own food and must obtain energy and nutrients by consuming other organic matter.
Heterotrophs
one organism benefits and the other is not affected
Commensalism
A diagram that shows how energy, biomass, or numbers of organisms decrease at higher levels.
Ecological Pyramid
Plants absorb nitrates and ammonia, incorporating them into amino acids and nucleic acids. Animals then consume these plants, passing the nitrogen up the food chain.
Assimilation
When plants and animals die, decomposers (like fungi and bacteria) break down their bodies, releasing trapped carbon into the soil or water.
Decomposition
are organisms that break down dead plants, animals, and waste products, recycling vital nutrients back into the ecosystem. They serve as nature's cleanup crew, ensuring that dead organic matter does not accumulate indefinitely.
Decomposers
one organism benefits while the other is harmed
Parasitism
the process by which nitrogen continually moves between the atmosphere, soil, water, and living organisms.
Nitrogen Cycle
When plants and animals die, or excrete waste, decomposers (bacteria and fungi) break down the organic matter and convert the nitrogen back into ammonia.
Ammonification
Over millions of years, some decomposed organic matter is buried deep underground under specific pressure and heat, turning into fossil fuels like coal, oil, and natural gas.
Burial & Sedimentation
A bear is a __________
heterotroph
a biological interaction where a predator organism captures and consumes a prey organism for energy
Predation
nature's way of reusing carbon atoms, which travel from the atmosphere into organisms in the Earth and then back into the atmosphere over and over again.
Carbon Cycle
Specialized bacteria in waterlogged soils or aquatic environments convert excess soil nitrates back into nitrogen gas, releasing it back into the atmosphere and completing the cycle
Denitrification
Humans extract these fossil fuels and burn them (along with wood and biomass) for energy. This combustion process rapidly releases massive amounts of CO2 into the atmosphere
Combustion
Earthworms are ___________
detritivores