physical change decomposer structures
cycle contract potential energy consumer
magnetism nonrenewable resource balance
magnetic food chain renewable resource
population experiment germinate
community migrate reptiles sound
extinct metamorphosis amphibians
evaporation rock ecosystem expand
rotation traits carnivore mixture
equator revolution invertebrate
kinetic energy herbivore erosion
endangered environment investigation
pollination solar system experiment
producer renewable solution mixture
conservation solution vibrations
dispersal vertebrate adaptation water
axis environment investigate system
mammals weathering condensation