human impact
when trees are removed from the ecosystem, there are fewer producers to absorb ______ ________.
what is carbon dioxide
breaks down biotic wastes and dead organisms
what are decomposers
_______, ________, and ________ all play roles in recycling carbon and oxygen.
what are producers, consumers, and decomposers
definition of a food chain
what is a series of events in which one organism eats another and obtains energy
how water moves through the planet
what is the water cycle
human activities also affect the levels of _____ and _______ in the atmosphere
what is carbon and oxygen
a diagram called an _____ _______ shows the amount of energy that moves from one feeding level to another food web
what is an energy pyramid
the process of changing free nitrogen into a usable form of nitrogen is called ______ _________.
what is nitrogen fixation
definition of a food web
what are overlapping food chains in an ecosystem
heavy drops of water falling to Earth as rain, snow, sleet, or hail.
what is precipitation
the process by which fertile land becomes desert, typically as a result of drought, deforestation, or inappropriate agriculture
what is desertification
an organism that can make its own food
what is a producer
when ________ and _________ die, decomposers break down their remains and return carbon molecules to the soil.
what are producers and consumers
food chains help animals gain ___
what is energy
when water absorbs energy and changes into a gas
what is evaporation
activity that includes equipment and chemicals that helps food grow
what is agriculture
a carnivore that feeds on the bodies of dead organisms
what is a scavenger
as consumers eat producers, they take in the ______-_________ _______
what are carbon-containing molecules
the difference between a food chain and a food web
one consists of many overlapping food chains and the other one is smaller and contains less animals
how condensation happens
condensation is when gas changes into liquid
main thing that effects ecosystems
what are human activities
different titles for consumers
what are herbivores, omnivores, scavengers, and carnivores
some human activities release ______ ______ into the air
what are carbon compounds
why food chains and food webs are important to animals and ecosystems
it is how energy moves from organism to organism in and ecosystem
the order in which the water cycle occurs
evaporation, condensation, precipitation, and run-off