Life and Earth Systems Vocabulary

Vocabulary flashcards covering the coevolution of life and Earth's systems, scientific methodology, soil formation, and environmental impacts.

Abiotic factor

The nonliving parts of the Earth system, such as climate, rocks, and ocean currents.

Biotic factor

Living organisms within an environment that interact with nonliving parts of the Earth system.

Biosphere

The Earth system that includes all life on the planet.

Coevolution

The process in which Earth's systems and life evolve together, where each changes in response to the other.

Theory

An explanation of phenomena backed by evidence that helps make predictions for the future.

Scientific law

A description of observable patterns in nature.

Falsifiable

The requirement that a scientific claim must be possible to prove wrong through testing and observation.

Goldilocks zone

The region around a star where the temperature is just right for liquid water to exist.

Luminosity

The intrinsic brightness of a star, measuring the energy it emits.

Astronomical unit (AU)

A unit of distance where Earth's orbit is located at approximately $1\,AU$ from the Sun.

Outgassing

The process by which volcanic activity releases gases, such as water vapor, from Earth's interior into the atmosphere.

Stromatolite

Rounded limestone structures formed by cyanobacteria, providing some of the oldest evidence of life on Earth.

Cyanobacteria

Simple, single-celled organisms that emerged approximately $3.5$ billion years ago and perform photosynthesis.

Natural selection

The process in which organisms better adapted to their environment survive and reproduce.

Photosynthesis

The process using Sun energy to combine $H_2O$ and $CO_2$ to produce oxygen and sugar ($C_6H_{12}O_6$).

Glucose

A sugar molecule ($C_6H_{12}O_6$) produced during photosynthesis that provides essential energy for ecosystems.

Oxidation

A weathering process where iron and sulfide compounds in Earth's crust react with oxygen.

Oxygen sink

Substances in Earth's crust that absorbed early oxygen, preventing it from accumulating in the atmosphere initially.

Anaerobic metabolism

Energy production that does not require oxygen, used by early life forms.

Aerobic metabolism

Oxygen-dependent energy production that allows for more energy and the development of complex body structures.

Ozone layer

A layer of $O_3$ in the upper atmosphere that blocks harmful ultraviolet (UV) radiation.

Cambrian explosion

A period of rapid growth in the diversity and complexity of multicellular life around $541$ million years ago.

Humus

The nonliving, decayed organic material that enriches soil with nutrients.

Soil horizon

A distinct layer in the soil profile created by the gradual formation of soil over time.

Leaching

The process by which heavy rainfall causes nutrients to wash out of the soil.

Coral polyp

Tiny animals that build limestone exoskeletons around their soft bodies to form reef structures.

Zooxanthellae

Microscopic algae hosted within coral tissues that provide energy through photosynthesis.

Atoll

A ring-shaped coral formation encircling a lagoon, formed as a volcanic island sinks into the ocean.

Mass extinction

An event causing the loss of a significant number of Earth's species over a large area.

Deforestation

The clearing of most trees in an area, which releases $CO_2$ and reduces natural carbon storage.

Ocean acidification

The decrease in ocean pH caused by the absorption of excess atmospheric $CO_2$, forming carbonic acid.

pH scale

A logarithmic scale where $7.0$ is neutral, lower numbers are acidic, and higher numbers are basic.

Calcifiers

Marine organisms that use calcium carbonate to build protective shells and exoskeletons.

Transpiration

The movement of moisture from plant roots to leaf pores where it is released as water vapor.

Evapotranspiration

The combined process of water lost from the Earth's surface through evaporation and plant transpiration.

Primary succession

The development of an ecosystem starting from bare rock without any significant life forms present.

Hydrothermal vents

Fissures on the ocean floor that flow with hot, mineral-rich water, likely home to the earliest life forms.

Atmosphere

The sphere of Earth consisting of air and gases surrounding the planet.

Hydrosphere

The sphere of Earth encompassing all water, including oceans and rain.

Lithosphere

The sphere of Earth consisting of land, rocks, and the planet's crust.

Greenhouse gases

Gases like $CO_2$, methane, and water vapor that trap heat to keep the planet warm.

Carbonic acid

A weak acid formed when carbon dioxide dissolves in atmospheric water or seawater.

Calcium carbonate

A compound used by calcifiers to build shells and which forms limestone rocks.

Evolution

A gradual process where life forms change over time, and current species arise from common ancestors.

Ecological succession

The process by which life returns to and regenerates a devastated area over time.

Fringing reef

A coral reef that grows outward from a volcanic island during the early stages of atoll formation.

Barrier reef

A coral reef that has separated from a sinking island, surrounding it with a lagoon.

Colonial organism

An organism, like coral, where a single individual divides to form connected daughter individuals.

Greenhouse effect

The natural process where gases trap heat in the atmosphere, stabilizing Earth's climate for life.

Limestone

A sedimentary rock formed from compounds like calcium carbonate, often found in stromatolites and coral reefs.