BJU Press Biology - Chapter 3

Biodiversity

refers to the number of species in an area

Biomes

Regions of the biosphere that share certain environmental conditions, such as climate, and have a certain set of organisms adapted to those conditions

Population

all the organisms of the same species and living in the same area

Habitat

the smaller part of an ecosystem that an organism prefers to live in

Niche

the way an organism lives in its habitat, including its effects on that habitat and on other organisms that share the habitat

Autotrophs

also known as producers; an organism that makes its own food

Biomass

the total amount of living matter that an ecosystem can support

Parasitism

exhibited when an organism depends on another organism for food, called the host.

Vertical Zonation

Ecological layers within a biome due to factors such as geographical elevation or depth of water

Symbiosis

the phenomenon of different animals living together and interacting with each other within a particular habitat.

Mutualism

two different organisms living together and interacting with each other in a way that benefits both organisms

Commensalism

When one organism benefits from the other but the other is neither helped nor harmed

Amensalism

one organism is injured while the other is unaffected

Neutralism

When two organisms live in the same neighborhood but don't pray on the same food items and aren't directly affected by one another

Detritus

waste products of plants and animals

Benthic Organisms

Organisms that live on the ocean floor

Pelagic Organisms

Organisms that swim or drift with the ocean currents

Climate

average weather in an area over an extended period of time constitutes an area's climate

Timberline

On a mountain, temperatures and precipitation are insufficient to grow trees above a certain elevation

Competition

When organisms try to use the same resource

Species Richness

Describes the number of species within an ecosystem

Species Evenness

Compares the population sizes of the species within an ecosystem

Abiotic Factors

Nonliving aspects of an ecosystem

Biotic Factors

Living parts of an ecosystem

Ecology

Study of the interrelationships between organisms and organisms of the same species, those of different species and their environment