Organism
A word used to describe any living thing
Habitat
An environment that provides the things an organism needs to live, grow, and reproduce.
Biotic Factors
The living parts of a habitat
Abiotic Factors
The nonliving parts of a habitat. (e.g. water, sunlight, oxygen, temperature, soil)
Photosynthesis
Process that allows plants to make their own food using the energy of the sun. This process happens in the chloroplasts of plant cells. This is an important process in the oxygen and carbon cycles on Earth.
(6 CO2 + 6 H2O ?SUNLIGHT? C6H12O6 + 6 O2 )
Cellular Respiration
Process that allows plants and animals to turn energy from food molecules, glucose, into an energy molecule, ATP, that can be used by cells. This process happens in the mitochondria of both plant and animal cells. This is an important process in the oxyge
Ecology
The study of how living things interact with each other and with their environment is called...
Species
A group of organisms that are physically similar and can mate with each other to produce offspring that can also mate and reproduce.
Population
All the members of one species in a particular area at a particular time.
Community
All the different populations that live together in a specific area at a particular time.
Ecosystem
The community of organisms that live in a particular area, along with their nonliving surroundings.
Consumer
An organism that obtains energy by feeding on other organisms.
Producer
An organism that can make its own food. They are the source of all the food in an ecosystem. (e.g. plants)
Decomposer
Organisms that break down wastes and dead organisms and return the raw materials to the ecosystem. (e.g. fungi and bacteria)
Carrying capacity
The largest population that an area can support.
Limiting factor
An environmental factor that causes a population to stop growing. (e.g. food, water, space, weather conditions)
Competition
Struggle between organisms for limited resources in a An environmental factor that causes a population to stop growing. (e.g. food, water, space, weather conditions).
Symbiosis
Relationship between two species in which at least one species benefits.
Commensalism
Relationship between two species in which one species benefits and one is unharmed. (+, 0)
Parasitism
When one organism, parasite, is living on or inside another organism and harming the host organism.
(+,-)
Predation
Interaction between two species in which one organism kills and eats another organism. (+,-)
Mutualism
Relationship between two species in which both species benefit. (+,+)
Succession
The series of predictable changes that occur in a community over time.
Primary succession
A series of predictable changes that occur in an area where no soil or organisms exist. (e.g. after a volcanic eruption)
Secondary succession
A series of predictable changes that occur in an area where the ecosystem has been disturbed, but where soil and organisms still exist. (e.g. after a fire)
Pioneer species
The first species to populate an area during primary succession. They help break down rock and turn it into soil. (e.g. lichens and mosses)
Herbivore
Consumer organism that only eats plants. (e.g. cows, deer, caterpillars)
Carnivore
Consumer organism that only eat animals. (e.g. lion, spiders)
Scavenger
A carnivore that feeds on the bodies of dead organisms. (e.g. vulture)
Immigration
When an individual is moving into a population.
Emigration
When an individual is leaving or exiting a population.
Keystone species
A species that influences the survival of many other species in an ecosystem. (e.g. sea otter in the kelp forests of the Coastal Pacific Ocean)
Niche
The way a species makes its living or the particular role of a species in an ecosystem.
Niche diversity
When a habitat supports many different niches for the organisms that live there. This enables more species to live in the habitat and leads to great biodiversity. (e.g. coral reefs)
Biodiversity
The number of different species in an area.
Threatened species
A species that could become endangered in the near future.
Endangered species
A species in danger of becoming extinct in the near future.
Extinction
The disappearance of all members of a species from Earth.
Adaptation
A behavior or physical characteristic that allows an organism to live successfully in its environment.
Natural selection
A process by which characteristics that make an individual better suited to its environment become more common in a species.
Gene pool diversity
Organisms in a healthy population have a diversity of traits. The organisms in one species share many genes, but each organism also has some genes that differ from those of other individuals. These differences in DNA are caused by mutations. These individ
Food chain
A series of events in which one organism eats another to obtain energy.
Food web
Made of many overlapping food chains in an ecosystem. This is a more realistic way to show energy flow through an ecosystem.
Biological energy pyramid
Represents the amount of energy that moves from one feeding level to another in a food web. The most energy is available at the producer level and as you move up the pyramid less and less energy is available.
Trophic levels of a food chain
The levels of producers and consumers in a food chain. (Trophic means the nutrition at each level.)
Omnivore
Consumer organism that eats both plants and animals. (e.g. crows, bears)