Scientific Method, Ecology, and Biogeochemical Cycles Vocabulary

Vocabulary practice flashcards generated from lecture notes covering the scientific method, general ecology, population metrics, biogeochemical cycles, and ecological interactions.

Observations

The process of obtaining information using all of your senses.

Hypothesis

An educated guess that answers a question, is testable, and is typically structured in an "if…then…" format.

Control Group

The group in a controlled experiment that provides the normal standard for comparison and does not receive the experimental variable.

Experimental Group

The group in an experiment that receives the treatment or factor being tested.

Independent Variable

The variable in an experiment that is manipulated or varied by the experimenter.

Dependent Variable

The variable measured by the experimenter that responds to or is affected by changes in the independent variable.

Qualitative Data

Data collected during an experiment that is recorded using word descriptions.

Quantitative Data

Data collected during an experiment that is recorded using numerical measurements or counts.

Inference

A conclusion drawn on the basis of facts and previous knowledge rather than direct observation.

Modeling

Constructing a representation of an object, system, or process to illustrate relationships among data.

Ecology

The study of the interactions of organisms with other organisms and with their surrounding environment.

Abiotic Factors

Non-living components that affect an organism, such as soil, water, and weather.

Biotic Factors

Living components that affect organisms, such as animals and plants.

Habitat

The place where organisms live and interact.

Biodiversity

The variety of species living within an ecosystem, biome, or planet.

Niche

The role or functional job a species plays within its community.

Autotroph

An organism (producer) that captures energy, such as sunlight, to create its own food.

Heterotroph

An organism (consumer) that must consume other organisms or organic matter to obtain energy.

Detritivore

A consumer that feeds on decaying organic material, rotting matter, or waste (e.g., earthworms, dung beetles, maggots).

Decomposer

Microorganisms or organisms, such as bacteria and fungi, that break down organic matter.

Food Chain

A linear pathway representing the directional flow of energy through feeding (trophic) relationships.

Food Web

A network of interconnected food chains reflecting realistic feeding interactions across multiple trophic levels.

10% Rule

The ecological principle stating that only $10\text{\%}$ of the energy stored in one trophic level is transferred to the next higher level.

Population Density

The number of individuals of a species living per unit area, calculated by dividing population size by area.

Dispersion

The spatial arrangement of individuals belonging to a population within a given area (uniform, random, or clumped).

Density-dependent Factors

Limited environmental resources (e.g., food, water) whose rates of depletion depend directly on population density.

Density-independent Factors

Environmental factors (e.g., climate, geography) that affect population growth regardless of population density.

Carrying Capacity ($k$)

The maximum number of individuals in a population that a given environment can sustainably support.

Exponential Model

A population growth model depicted by a "J" shaped curve showing rapid, unrestricted population increase.

Logistic Model

A population growth model depicted by an "S" curve where exponential growth is slowed by density-dependent limiting factors.

r-Strategists

Opportunistic species that reproduce in high quantity with low investment, experiencing fluctuating densities in open habitats with little competition.

K-Strategists

Equilibrium species that focus on quality over quantity, keeping population density hovering near carrying capacity.

Biogeochemical Cycles

Processes that circulate essential nutrients and elements through the air, water, soil, rock, and living organisms.

Water Cycle

The continuous movement of water above, on, and below the Earth's surface through processes like evaporation, condensation, precipitation, transpiration, infiltration, and percolation.

Carbon Cycle

The movement of carbon between the atmosphere, organisms, soil, fossil fuels, and factory emissions via photosynthesis, respiration, decay, and combustion.

Nitrogen Cycle

The cycling of nitrogen compounds between atmospheric $N_2$ and biological forms through nitrogen fixation, ammonification, nitrification, assimilation, and denitrification.

Phosphorus Cycle

The movement of phosphate ($PO_4^{3-}$) through rock weathering, plant absorption, animal incorporation, decomposition, leaching, and ocean sediment formation.

Symbiosis

Any close and prolonged association or relationship between members of two or more different species.

Mutualism

A symbiotic interaction in which both participating species receive mutual benefits.

Commensalism

A symbiotic relationship in which one organism benefits while the other is neither helped nor harmed.

Parasitism

A symbiotic relationship in which one organism (the parasite) benefits at the expense of another (the host), which is harmed.

Predation

An interaction where one species benefits by killing and consuming another organism for energy.

Intraspecific Competition

Competition for shared limited resources occurring between individuals of the same species.

Interspecific Competition

Competition for shared limited resources occurring between individuals of two or more different species.