APES Notes: Energy, Systems, and the Scientific Method

Vocabulary flashcards covering key terms from the notes. Each card provides a term and a concise definition.

Energy transfer

The movement of energy through systems, where energy changes form but is not created or destroyed.

Interactions between Earth systems

Processes by which the atmosphere, hydrosphere, lithosphere, and biosphere influence one another.

Interactions between different species

Ecological relationships among species, such as predation, competition, and symbiosis.

Sustainability

The ability to meet present needs without compromising the ability of future generations to meet theirs.

Scientific method

A systematic process for investigating phenomena, testing predictions, and refining explanations.

Hypothesis

A testable conjecture or educated guess about a relationship between variables.

Independent variable

The variable deliberately changed by the researcher in an experiment.

Dependent variable

The variable measured to assess the effect of the independent variable.

Null hypothesis

A statement that there is no difference or effect between groups or conditions.

Control group

A baseline group not exposed to the experimental treatment.

Experimental group

The group that receives the treatment or variable being tested.

Natural experiment

A natural event that acts as an experimental treatment in an ecosystem.

Replication

Repeating measurements or experiments to ensure reliability and reduce random error.

First law of thermodynamics

Energy cannot be created or destroyed, only transformed.

Second law of thermodynamics

In energy transformations, usable energy decreases while total energy remains constant; entropy increases.

Abiotic

Nonliving components of an environment.

Biotic

Living components of an environment.

Germination triggered by wildfires

Some plant species germinate after fire due to environmental cues.

Long-term environmental change (10k–20k years)

Over thousands of years, human activity and natural processes substantially alter resources and ecosystems.

Extinction examples (Passenger pigeons, mammoths, giant sloths)

Species driven to extinction due to human activity and environmental change.

Native Americans and ecosystem resources

Indigenous use of ecosystem resources that affected landscapes and species.

Energy flow and degradation

As energy moves through systems, its usable energy quality degrades, influencing system dynamics.

Observation

Careful noticing and recording of phenomena that lead to questions and hypotheses.

Prediction

A stated expected outcome derived from a hypothesis.

Sample size

The number of observations in a study; small samples can mislead results.

Accuracy

Closeness of measurements to the true value.

Precision

Closeness of repeated measurements to each other (consistency).

Inductive reasoning

Reasoning from specific observations to general conclusions.

Deductive reasoning

Reasoning from general principles to specific conclusions.

Natural law

A widely accepted principle with no known exceptions after rigorous testing.