Biology 20 Unit B - Ecosystems & Population Change Flashcards

Vocabulary practice flashcards covering key terms and concepts in ecology, ecosystems, classification, and evolution from Biology 20 Unit B.

Ecology

The study of organisms and their relationship to one another and their biotic and abiotic environment.

Ecologist

A scientist who studies the biosphere as a whole, including living organisms, populations, communities, and ecosystems.

Ecosystem

A group of living organisms that interact with their non-living environment to form a self-regulating system through which energy and materials transfer.

Species

A group of organisms that can naturally interbreed to produce fertile offspring.

Population

All the members of one species living within a specific area.

Community

All the different species found within a given habitat.

Ecotone

A transition zone from one ecosystem to another, typically possessing greater biodiversity and stability than neighboring ecosystems.

Biodiversity

The variety and number of different types of species present in an ecosystem.

Biome

An area defined by characteristic geographic and climatic patterns that support specific plant and animal populations.

Biosphere

The entire region on Earth where life is sustained.

Ecological Niche

The specific role a population plays within its ecosystem, including its food web placement, breeding area, active hours, and interspecies relationships.

Exotic Species

A non-native, alien, or invasive species introduced to an ecosystem that can compete for a niche with native species and potentially eliminate them.

Taiga

A northern and central Alberta terrestrial ecosystem dominated by cone-bearing, needle-leaf coniferous trees like pine and spruce in acidic soil.

Grassland

A southern Alberta terrestrial ecosystem characterized by fertile black soil, high sunlight, low precipitation, and dominated by grasses and grazers.

Muskeg

A swampy bog ecosystem in the northern taiga characterized by permafrost beneath acidic soil, peat, black spruce trees, and very slow decomposition.

Deciduous Forest Ecosystem

An ecosystem located between grassland and taiga biomes dominated by leaf-losing trees like aspen poplar and birch, featuring rich leaf litter, high diversity, and high biomass.

Littoral Zone

The zone of a lake extending from the shore to the depth where rooted aquatic plants stop growing.

Limnetic Zone

The open-water area of a lake receiving sufficient light for photosynthesis, abundant in phytoplankton and zooplankton.

Profundal Zone

The deep, open-water region of a lake located below the limit of effective light penetration, where decomposers process sinking detritus.

Oligotrophic Lakes

Deep, cold lakes with low nutrient levels, clear water, and small producer and animal populations.

Eutrophic Lakes

Shallow, warm lakes rich in nutrients, with murky water and large populations of producers and animals.

Eutrophication

The natural or human-accelerated process in which an oligotrophic lake transforms into a nutrient-rich eutrophic lake and eventually dries up into land.

Carrying Capacity

The maximum number of individuals of a species that an ecosystem can support, representing a balance between biotic potential and environmental resistance.

Biotic Potential

The theoretical maximum growth rate of a population, determined by birth potential, survival capacity, breeding frequency, and length of reproductive life.

Density Independent Limiting Factors

Environmental factors that reduce population size regardless of population density, such as floods, fires, climate change, drought, or pesticide spraying.

Density Dependent Limiting Factors

Environmental factors whose intensity increases as population density grows, such as competition for food, water, space, and predation.

Interspecific Competition

Competition for resources between individuals of different species.

Intraspecific Competition

Competition for resources among members of the same species within a niche.

Taxonomy

The theory and practice of identifying, naming, and classifying organisms.

Taxon

Any unit or group of organisms treated as a named rank in a classification system.

Binomial Nomenclature

The formal system of naming species using a two-part scientific name consisting of the capitalized genus name and the uncapitalized species name.

Dichotomous Key

A taxonomic identification tool that divides organisms into two contrasting choices at each step based on observable characteristics.

Microevolution

Changes in gene frequencies within a single population's gene pool from one generation to the next.

Macroevolution

Large-scale evolutionary patterns and history of species formation over long periods of geological time.

Natural Selection

The mechanism of evolution where organisms best adapted to their environment survive and reproduce, passing favorable inherited traits to offspring.

Inheritance of Acquired Characteristics

Jean-Baptiste Lamarck's disproved theory that modifications developed by an organism during its lifetime through use or disuse are inherited by its offspring.

Geographic Isolation

The physical separation of populations by geographical barriers like mountains, rivers, canyons, or glaciers, halting gene flow and promoting speciation.

Gradualism

The macroevolutionary model proposing that speciation occurs through the slow, continuous accumulation of small genetic changes over geological time.

Punctuated Equilibrium

The macroevolutionary model proposing long periods of evolutionary stasis punctuated by brief bursts of rapid speciation.

Radiocarbon Dating

An absolute dating technique measuring the decay of radioactive carbon-14 (half-life of 5,700 years) relative to carbon-12 in organic remains.

Biogeography

The study of the geographic distribution of living organisms and fossil evidence across the continents.

Vestigial Structures

Anatomical remnants or organs that have reduced size and lost their original function over evolutionary history.

Homologous Structures

Anatomical structures across different species that share a common ancestral origin and structural plan, though adapted for different functions.

Analogous Structures

Body structures in different species that perform similar functions but evolved independently without shared ancestry.