| A | B |
| Birthrate | number of births in a population at a certain time |
| soil profile | all the layers that make up the soil |
| soil | loose top layer of the earth's surface |
| food web | describe a complex pattern of the flow of energy, larger than food chain |
| energy pyramid | shows the amount of energy that moves from one thropic level to another |
| biotic factor | living part of an ecosystem |
| abiotic factor | nonliving part of an ecosystem |
| food chain | what an organism eats and who eats it |
| habitat | where an organim lives and gets its food, water, shelter |
| population | all the individuals of the same species in a given area |