Chapter 3

Front 1

Ecology

Back 1

the scientific study of interactions among organisms and between organisms and their environment.

Front 2

Biosphere

Back 2

the combined parts of the Earth in which all life exists, including land, air and water. The highest level of organization that scientists study.

Front 3

Individual / Organism

Back 3

a single individual from one species; the smallest level of organization that scientists study.

Front 4

Population

Back 4

Groups of individuals that belong to the same species and live in the same area. One of the levels of organization that scientists study.

Front 5

Community

Back 5

assemblages of different populations that live together in a defined area. One of the levels of organization that scientists study.

Front 6

Ecosystem

Back 6

A collection of all the organisms that live in a particular place, together with the nonliving factors of the environment (such as the air, water, soil, etc.). One of the levels of organization that scientists study.

Front 7

Biome

Back 7

a group of ecosystems that have the same climate and similar dominant animal and plant life. One of the levels of organization that scientists study.

Front 8

Species

Back 8

A group of organisms so similar to one another that they can breed and produce fertile offspring. One of the levels of organization that scientists study.

Front 9

Observing

Back 9

One of the approaches for conducting modern ecological research. It is also the first step in asking ecological questions.

Front 10

Experimenting

Back 10

One of the approaches for conducting modern ecological research. Using the scientific method, it is used to test hypotheses.

Front 11

Modeling

Back 11

One of the approaches for conducting modern ecological research. It can be mathematical formulas based on data collected through observation and experimentation. Computer animations and simulations are also examples.

Front 12

Autotroph

Back 12

organisms that can capture energy from sunlight or chemicals and use it to produce its own food from inorganic compounds; also called a producer

Front 13

Producer

Back 13

organisms that can capture energy from sunlight or chemicals and use it to produce its own food from inorganic compounds; also called an autotroph

Front 14

Photosynthesis

Back 14

process by which plants and some other organisms use light energy to convert water and carbon dioxide into oxygen and high energy carbohydrates such as sugars and starches

Front 15

Chemosynthesis

Back 15

process by which some organisms, such as bacteria, use chemical energy to form carbohydrates

Front 16

Heterotroph

Back 16

organism that relies on other organisms for energy and food supply; also called a consumer

Front 17

Consumer

Back 17

organism that relies on other organisms for energy and food supply; also called a heterotroph

Front 18

Herbivore

Back 18

organism that obtains energy by eating plant matter; for example, horses, cattle, rabbits, goats

Front 19

Omnivore

Back 19

organism that obtains energy by eating both plants and animals; for example, humans, bears, raccoons

Front 20

Detritivore

Back 20

organism that feeds on plant and animal remains and other dead or decaying matter; for example, a vulture, earthworm, or insects

Front 21

Decomposer

Back 21

organism that breaks down and obtains energy from dead or decaying matter; for example, bacteria and fungi

Front 22

Food chain

Back 22

series of steps in an ecosystem in which organisms transfer energy by eating and being eaten

Front 23

Food web

Back 23

network of complex interactions formed by the feeding relationships among the various organisms in an ecosystem

Front 24

Trophic level

Back 24

a step / link in a food chain or food web

Front 25

ecological pyramid

Back 25

diagram that shows the relative amounts of energy or matter within each trophic level in a food chain or food web

Front 26

biomass

Back 26

total amount of living tissue in a given trophic level

Front 27

biogeochemical cycle

Back 27

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.

Front 28

evaporation

Back 28

one part of the hydrologic (water ) cycle; process by which water changes from a liquid into an atmospheric gas.

Front 29

transpiration

Back 29

one part of the hydrologic (water ) cycle; loss of water from a plant through its leaves.

Front 30

condensation

Back 30

one part of the hydrologic (water ) cycle; the conversion of water vapor or gas to a liquid.

Front 31

precipitation

Back 31

one part of the hydrologic (water) cycle; rain, snow, sleet, or hail that falls to the ground

Front 32

nutrient

Back 32

chemical substance that an organism requires to live

Front 33

nitrogen fixation

Back 33

process of converting nitrogen gas into ammonia or nitrates/nitrites (by bacteria)

Front 34

denitrification

Back 34

process of converting ammonia into nitrogen gas (by bacteria)

Front 35

primary productivity

Back 35

rate at which organic matter is created by producers in an ecosystem

Front 36

limiting nutrient

Back 36

single nutrient that is either scarce or cycles very slowly, limiting the growth of organisms in an ecosystem.

Front 37

carbon cycle

Back 37

biogeochemical cycle by which atmospheric carbon dioxide is converted to carbohydrates by plants and other photosynthesizers, consumed and metabolized by organisms, and returned to the atmosphere through respiration, decomposition, and the combustion of fossil fuels.

Front 38

nitrogen cycle

Back 38

biogeochemical cycle by which nitrogen and its compounds are interconverted in the environment and in living organisms, including nitrogen fixation and decomposition.

Front 39

phosphorus cycle

Back 39

biogeochemical cycle that describes the movement of phosphorus through the lithosphere, hydrosphere, and biosphere.

Front 40

algal bloom

Back 40

an immediate increase in the amount of algae and other producers that results from a large input of a limiting nutrient (such as phosphorus or nitrogen); such as from fertilizer runoff