ch.5 Env terms (shortened)

Gene

A segment of DNA on a chromosome that codes for a specific trait

gene pool

Combined genetic information of all the members of a particular population

biological evolution

the change over time in populations of related organisms

Mutation

An accidental change in a gene or chromosome.

natural selection

A process in which individuals that have certain inherited traits tend to survive and reproduce at higher rates than other individuals because of those traits.

Fitness

Ability of an organism to survive and reproduce in its environment

Adaptation

A trait that helps an organism survive and reproduce

artifical selection

the selective breeding of organisms by humans for specific characteristics

speciation

Formation of new species

extinction

the loss of an entire species from Earth

Producer

An organism that can make its own food.

Consumer

An organism that obtains energy by feeding on other organisms

Photosynthesis

Conversion of light energy from the sun into chemical energy.

Chemosynthesis

process in which chemical energy is used to produce carbohydrates

trophic level

Each step in a food chain or food web

biomass

the total mass of organisms in a given area or volume.

keystone species

A species that influences the survival of many other species in an ecosystem

pioneer species

First species to populate an area during primary succession

ecological succession

gradual change in living communities that follows a disturbance

lichen

colorful, flaky patches that grow on rock (symbiotic association between an algae and a fungus)

climax community

A stable, mature community that undergoes little or no change in species over time

invasive species

species that enter new ecosystems and multiply, harming native species and their habitats