Chapter 3: The Biosphere

Herbivores

Obtain energy and nutrients by eating plant leaves, roots, seeds, or fruits

Ecology

The scientific study of interactions among organisms and between organisms and their environment

Scavengers

Animals that consume the carcasses of other animals that have been killed by predators or have died of other causes

Chemical

________ and physical processes include the formation of clouds and precipitation, as well as the flow of running water and the action of lightning.

Phosphorus

________ is mined, turned into fertilizer, and applied to crops.

Nitrogen gas

________ is turned into fertilizer and applied to crops.

heterotroph

An organism that obtains food by consuming other living things

Carbon dioxide

________ dissolves in oceans and returns to the atmosphere.

Detritivores

Chew or grind detritus particles into smaller pieces

Omnivores

Animals that eat both plants and other animals

Geological activity

________ turns marine sediments into rock and releases carbon dioxide.

Biogeochemical cycle

A 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

Denitrification

The process by which soil bacteria convert nitrates into nitrogen gas

Ecosystem

All the organisms that live in a place, together with their physical environment

Human activity

________ such as mining and burning fossil fuels and forests affect the cycles of matter.

Decomposers

"Feed" by chemically breaking down organic matter

Biosphere

Our entire planet, with all its organisms and physical environments

Water

________ falls to the surface as precipitation.

Carnivores

Kill and eat other animals

Consumer

An organism that relies on other organisms for its energy and food supply

Biome

A group of ecosystems that share similar climates and typical organisms

Food chain

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

organic matter

Decomposition, pressure, and heat turn ________ to fossil fuel over millions of years.

Surface runoff

________ leads through rivers to lakes and oceans.

Nutrients

Chemical substances organisms need to build tissues and carry out life functions

Population

A group of individuals that belong to the same species and live in the same area

Abiotic factor

A physical or nonliving factor that shapes an ecosystem

Biotic factor

Any living part of the environment with which an organism might interact

Biological processes

Consist of any and all activities performed by living organisms

Ecological pyramid

An illustration of the relative amounts of energy or matter contained within each trophic level in a given food chain or food web

freshwater environments

In ________, phosphorous is typically the limiting nutrient.

saltwater environments

In ________, nitrogen is typically the limiting nutrient.

Phosphorus

________ is taken up by primary producers, reused by consumers, and released by excretion and decomposing matter.

nitrogen gas

Some ________ is fixed by lightning.

Carbon dioxide

________ dissolves in rainwater.

Water

________ from oceans and lakes evaporates and then condenses to form clouds.

Geological activity

Turns marine sediments into rock

Carbon dioxide

________ is taken up by producers during photosynthesis and released by cellular respiration.

Nitrogen gas

________ is taken up by primary producers, reused by consumers, and released by excretion and decomposing matter.

Environment

Refers to all conditions, or factors, surrounding an organism

Pyramids of energy

Show the relative amount of energy available at each trophic level of a food chain or food web

Pyramids of biomass

Illustrate the relative amount of living tissue available at each trophic level in an ecosystem

Pyramids of numbers

Show the relative number of organisms at each trophic level

primary producer

The first producer of energy-rich compounds that are later used by other organisms

Autotroph

An organism that is able to capture energy from sunlight or chemicals and use it to produce its own food from inorganic compounds

Trophic level

Each step in a food chain or a food web

Primary productivity

The rate at which primary producers create organic material

Limiting nutrient

A nutrient whose supply limits productivity