From their surroundings, living things obtain food, water, shelter, and other things they need to live, grow and reproduce.
A single organism belongs to a population that includes other memebers of its species. The population belongs to a community of different species. The community and abiotic factors together form an ecosystem.
Every organism has a variety of adaptations that are suited to its specific living conditions.
There are three major types of interactions among organisms: competition, predation, and symbiosis. The three types of symbiotic relationships are mutualism, commensalism, and parasitism.
Each of the organisms in an ecosystem fills the enrgy role of producer, consumer, or decomposer. The moveemnt of energy through an ecossytem can be shown in a diagram called food chains and food webs.
The water, carbon and nirogen cycles are responsible for moving much of the earth's matter continuously through ecosystems. The water cycle is a continuous process by which water moves from Earth's surface to the atmosphere and back. Producers, consumers, and decomposers recycle carbon. In the nitrogen cycle, nitrogen moves from the air to the soil, into living things, and back into the air.