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final exam vocab
15 flashcards for Mrs. Brodbeck's Science semester 1 final exam
Term | Definition |
---|---|
permafrost | soil, rock or sediment that is frozen for more than two consecutive years. In areas not overlain by ice, it exists beneath a layer of soil, rock or sediment, which freezes and thaws annually and is called the "active layer". |
estuary | the tidal mouth of a large river, where the tide meets the stream |
population density | the number of individuals in a given area |
exponential growth | when individuals in a population reproduce at a constant rate - need unlimited resources (J-curve graph) |
logistic growth | when a population's growth rate slows and stops after a period of exponential growth - happens when a populations gets too large (s-curve graph) |
symbiosis | any relationship in which 2 species live closely |
adaptation | any characteristic of an organism which makes that organism better suited to its environment |
independent variable | a variable whose variation does not depend on that of another |
dependent variable | a variable whose value depends on that of another |
control group | the group in an experiment or study that does not receive treatment by the researchers and is then used as a benchmark to measure how the other tested subjects do |
experimental group | the group that receives an experimental procedure or a test sample. This group is exposed to changes in the independent variable being tested. |
sustainable forestry | process of planting young trees after cutting down trees, in order to maintain a constant supply of trees |
density-dependent limiting factors | depends on the size of the population and becomes a factor when the population is large |
density-independent limiting factors | affects the population regardless of the size |
biodiversity | the number of different species in an area |