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8th Science Review
An 8th Grade Science Review
Term | Definition |
---|---|
Law of Superposition | as layers get deeper, they also get older |
Catastrophism | the idea that quick and violent events change Earth |
Uniformitarianism | the idea that things happening on Earth now also happened in the past |
Radiometric Dating | figuring out the age of an object using its isotopes |
Index Fossil | a fossil that can help figure out the age of its surroundings |
Natural Selection | the idea that good traits will survive and change animals over time |
Variation | a difference in a trait |
Mutation | a random genetic change |
Adaptation | a trait that helps an organism survive or reproduce |
Vestigial Structure | a structure that is no longer needed, but is still there |
Pathogen | a disease making organism: there are 4 types (Bacteria, Virus, Fungi, Protists) |
Vector | anything that carries or gives a disease to another organism |
Disease | a condition that is not normal, and affects an organism |
Epidemic | when a disease spreads quickly and widely in small area |
Pandemic | when a disease spreads quickly and widely in a large area/world wide |
Nuclear Power | it makes a lot of power and is safe when you mine, but it creates toxic waste |
Hydroelectric Power | renewable and creates no pollution, but it destroys the homes of some animals |
Solar Power | renewable and is getting better, but it is expensive and the sun isn't always shining |
Wind Power | renewable and can be used at night, but it only works when there is wind |
Natural Gas | cleanest fossil fuel and and doesn't leave anything dangerous behind, but it is nonrenewable |
Coal Power | we are already using it across the world and always provides power, but it is nonrenewable and harmful |
Renewable | a resource that you won't run out of |
Nonrenewable | a resource that you can run out of |
Fossil Fuels | the remains of plants and animals that died millions of years ago |