Species
Is a group of similar organisms that can breed and produce fertile offspring.
Population
Is a group of individuals that belong to the same species and live in the same area.
Community
An assemblage of different populations that live together in a defined area.
Ecology
The scientific study of interactions among organisms and between organisms and their physical environment.
Ecosystem
All the organisms that live in a place, together, with their physical environment.
Biotic Factor
Any living part of the environment with which an organism might interact, including animals, plants, mushrooms, and bacteria.
Abiotic Factor
Any nonliving part of the environment, such as sunlight, heat precipitation, humidity, wind or water currents, soil type, and so on.
Autotroph
Organism that is able to capture energy from sunlight or chemicals and use it to produce its own food from inorganic compounds; also called a producer.
Primary Producer
First producer of energy-rich compounds that are later used by other organisms.
Photosynthesis
Process used by plants and other autotroph to capture light energy and use it to power chemical reactions that convert carbon dioxide and water into oxygen and energy-rich carbohydrates such as sugars and starches.
Heterotroph
Organism that obtains food by consuming other living things; also called a consumer.
Consumer
Organism that relies on other other organisms for its energy and food supply; also called a heterotroph.
Carnivore
Organism that obtains energy by eating animals.
Herbivore
Organism that obtains energy by eating only plants.
Scavenger
Animal that consumes the carcasses of other animals.
Omnivore
Organism that obtains energy by eating both plants and animals.
Decomposer
Organism that breaks down and obtains energy from dead organic matter.
Detritivore
Organism that feeds on plant and animal remains and other dead matter.
Biogeochemical Cycle
Process in which elements, chemical compounds, and other forms of matter are passed from one organism to another and from one part of the biosphere to another.
Nutrient
Chemical substance that an organism needs to sustain life.