Scienece midterm flashcrads

Biology

The study of living organisms and life processes.

Environmental Science

The interdisciplinary study of how humans interact with the environment, combining aspects of biology, chemistry, geology, and social sciences.

Renewable Natural Resources

Resources that can be replenished naturally over short periods, such as sunlight, wind, and water.

Nonrenewable Natural Resources

Resources that form over geological timescales and cannot be readily replenished, such as fossil fuels, minerals, and metals.

Ecosystem Services

Benefits provided by ecosystems that support life and human economies, including pollination, water purification, climate regulation, and nutrient cycling.

Agricultural Revolution

The transition from hunting and gathering to farming, leading to population growth and permanent settlements.

Industrial Revolution

A shift from manual labor and agrarian societies to mechanized industry, leading to technological advancements, increased fossil fuel use, and urbanization.

Fossil Fuels

Energy sources like coal, oil, and natural gas that formed from the remains of ancient organisms.

Ecological Footprint

The environmental impact of an individual or population based on resource use.

Overshoot

When resource consumption exceeds Earth's capacity to regenerate those resources.

Conservation

Sustainable use of natural resources.

Preservation

Protection of natural resources from use.

Natural Capital

Earth's resources and ecosystem services that sustain human life and economies.

Sustainability

Using resources in a way that meets present needs without compromising future generations.

Environmental Literacy

Understanding environmental issues, scientific principles, and sustainability concepts to make informed decisions.

Tragedy of the Commons

A situation where individuals overuse a shared resource, leading to depletion.

Independent Variable (IV)

The variable that is changed in an experiment.

Dependent Variable (DV)

The variable that is measured in an experiment.

Controlled Variables

Factors kept constant in an experiment.

Experimental Group (EG)

The group exposed to the independent variable.

Control Group (CG)

The group not exposed to the independent variable for comparison.

Biosphere

The global sum of all ecosystems.

Lithosphere

Earth's solid outer layer.

Atmosphere

The layer of gases surrounding Earth.

Hydrosphere

All water on Earth.

Ecosystem

A system of interacting organisms (biotic factors) and their environment (abiotic factors).

Biotic Factors

Living components (plants, animals, bacteria).

Abiotic Factors

Non-living components (water, sunlight, soil).

Producers

Organisms that make their own food (plants, algae).

Consumers

Organisms that eat other organisms (herbivores, carnivores).

Decomposers

Organisms that break down organic material (fungi, bacteria).

Detritivores

Organisms that consume dead material (earthworms, vultures).

Heterotroph

An organism that gets energy from eating others (consumers).

Autotroph

An organism that makes its own energy via photosynthesis (producers).

Gross Primary Productivity (GPP)

The total energy produced by plants.

Net Primary Productivity (NPP)

Energy available to consumers after plants use some for respiration.

Trophic Levels

Energy decreases by 90% as it moves up levels; only 10% is passed on.

Biomass

The total mass of living organisms in an area.

Positive Feedback

Amplifies changes (climate change).

Negative Feedback

Stabilizes systems (body temperature regulation).

First Law of Thermodynamics

Energy cannot be created or destroyed.

Second Law of Thermodynamics

Energy transfer increases entropy (disorder).

Source

Releases a material (CO₂ emissions).

Sink

Absorbs a material (forests, oceans).

Species

A group of organisms that can reproduce.

Population

A group of the same species in an area.

Evolution

Genetic change over generations.

Natural Selection

Survival of the fittest.

Extinction

The permanent loss of a species.

Endemic Species

Species found only in one area.

Sixth Mass Extinction

The current human-driven extinction crisis.

Levels of Ecological Organization

Organism → Population → Community → Ecosystem → Biosphere.

Habitat

Where an organism lives.

Niche

The role an organism plays in the ecosystem.

Population Growth Rate Equation

(Births - Deaths) + (Immigration - Emigration).

Exponential Growth

J-curve; rapid population increase.

Logistic Growth

S-curve; growth slows at carrying capacity.

Carrying Capacity

The maximum population an environment can support.

Density-Dependent Factors

Affected by population size (disease, food supply).

Density-Independent Factors

Unaffected by population size (natural disasters).

Food Chain

A single pathway of energy flow in an ecosystem.

Food Web

Interconnected feeding relationships within an ecosystem.

Energy Transfer

90% lost as heat at each trophic level.

Intraspecific Competition

Competition within the same species.

Interspecific Competition

Competition between different species.

Mutualism

Both species benefit.

Commensalism

One species benefits, the other is unaffected.

Parasitism

One species benefits, the other is harmed.

Keystone Species

A species critical for ecosystem stability (e.g., wolves in Yellowstone).

Trophic Cascade

Changes in one trophic level affect others.

IPAT Model

Impact = Population × Affluence × Technology.

Pre-Industrial Stage

High birth and death rates.

Transitional Stage

Death rates drop, birth rates remain high.

Industrial Stage

Birth rates decline.

Post-Industrial Stage

Low birth and death rates.

Education and Fertility

More education leads to lower birth rates.

Causes of Extinction

Habitat destruction, climate change, pollution, overharvesting, and invasive species.

Background Extinction Rate

Natural, slow rate of species loss (~1 species per million per year).

Current Extinction Rate

100–1,000 times higher due to human activities.

Habitat Fragmentation

The division of large habitats into smaller, isolated patches.

Edward O. Wilson

Biologist known for biodiversity and sociobiology; proposed the Theory of Island Biogeography and Half-Earth Theory.

Biodiversity

The variety of life, including genetic, species, and ecosystem diversity.

Causes of Biodiversity Loss

Habitat loss, pollution, overharvesting, invasive species, climate change.

Generalists (Winners)

Adaptable, broad diet, thrive in human-altered environments (e.g., raccoons, cockroaches).

Specialists (Losers)

Narrow habitat/diet, sensitive to environmental changes (e.g., pandas, coral reefs).

Biodiversity Hotspot

Areas with high biodiversity and many endemic species under threat.

Examples of Biodiversity Hotspots

Amazon Rainforest, Madagascar, Coral Triangle.

Ways to Prevent Biodiversity Loss

Protected areas, anti-poaching laws, ecosystem restoration, sustainable resource use, reducing pollution, ecotourism.