Biology Term Exam Review: Ecology, Evolution, and Classification

Vocabulary flashcards covering experimental design, taxonomy and classification, population ecology, and evolutionary mechanisms from the Term Exam Review.

Hypothesis

a narrow set of natural phenomena based on prior experience, background knowledge, and observations that can be tested.

Manipulated Variable

The independent variable in a scientific experiment; the variable that is being changed by the investigator.

Responding Variable

The dependent variable in a scientific experiment; the factor that changes in response to the manipulated variable.

Control Group

The group in an experiment that does not receive the manipulated variable and is kept unchanged for comparison purposes.

Experimental Group

The group in a scientific experiment that receives the manipulated variable so that the resulting response can be measured.

Constant Variables

Conditions or factors that are kept identical across all experimental and control groups.

Theory

A broad, explanation for natural phenomena that has been repeatedly tested, is strongly supported by evidence, and can be used to make predictions.

Controlled Experiment

An experimental setup containing a manipulated variable, responding variable, constant variables, a control group, and an experimental group to limit human and experimental error.

Taxonomy

A hierarchical system for naming and classifying organisms, as well as the biological studying evolutionary relatednessbetween species.

Binomial Nomenclature

A two-part naming system developed by Linnaeus consisting of the capitalized genus name followed by the lowercase species name, typically written in Latin and italics.

Taxon (Taxa)

A ranking level or organizational group in Linnaeus' classification system into which living organisms are organized.

Genus

A taxonomic category consisting of a group of closely related species; constitutes the first capitalized word in binomial nomenclature.

Species

A group of similar organisms that can interbreed in nature and produce viable, fertile offspring that can also interbreed.

Common Ancestor

An ancestral organism to which two or more distinct descendant lineages are historically related.

Derived Character

A specific trait or characteristic that separates and distinguishes lineages from one another on a phylogenetic tree.

Outgroup

The organism or lineage in a phylogenetic tree that branches off earliest and is least closely related to the remaining organisms.

Phylogenetic Tree

A branching diagram that illustrates evolutionary relationships and relatedness among various biological species.

Prokaryote

A single-celled organism lacking a nucleus and membrane-bound organelles, possessing a single circular chromosome.

Eukaryote

An organism characterized by cells containing a distinct nucleus, membrane-bound organelles, and multiple linear chromosomes.

Autotroph

An organism that synthesizes its own organic energy source rather than consuming other organisms.

Photoautotroph

An autotrophic organism that converts light energy from the sun into usable chemical energy.

Chemoautotroph

An autotrophic organism that converts one kind of chemical energy into another form of chemical energy.

Heterotroph

An organism that obtains energy and organic nutrients by consuming other living or dead organisms.

Ingestive Heterotroph

A heterotroph that ingests (eats) other organisms to obtain energy.

Absorptive Heterotroph

A heterotroph that releases specialized chemical enzymes to digest organic matter externally before absorbing the nutrients.

Population

A group of individuals that belong to the same species and inhabit the same defined geographic area.

Range

The geographic area in which a species can be found, often represented cartographically on a map.

Density

The total number of individuals of a population per unit of area or volume.

Distribution

The spatial pattern or arrangement in which individuals of a population are dispersed across their geographic range.

Clumped Distribution

A spatial dispersion pattern seen in social organisms living in colonies, family groups, swarms, or where resources are patchy.

Uniform Distribution

A dispersion pattern where individuals maintain even, regular spacing from one another due to territoriality or competition.

Random Distribution

A dispersion pattern where individuals show no regular spatial arrangement, typically resulting from minimal social interactions.

Growth Rate

A population metric indicating whether population size is increasing, decreasing, or constant, governed primarily by birth rate and death rate.

Exponential Growth

Population growth proceeding at a constant rate of increase per unit of time, producing a characteristic J-shaped curve.

Logistic Growth

Population growth that increases at a constant amount per unit of time before slowing and leveling off as resources become limited.

Carrying Capacity

The maximum number of individuals of a given species that a specific environment can sustainably support.

Density Dependent Limiting Factor

An environmental factor that restricts population growth once population density exceeds a certain threshold (e.g., competition, predation, parasitism, disease, and stress from overcrowding).

Density Independent Limiting Factor

An environmental factor that affects population size regardless of its density (e.g., severe weather such as floods or droughts, and natural disasters like fires or earthquakes).

Albedo Effect

The measure of solar radiation reflected by a surface, scored from 0 to 1; a decrease in snow cover reduces reflectivity, causing greater heat absorption and temperature increases.

Carbon Sink

A natural or artificial reservoir that collects and stores carbon-containing compounds from the environment.

Greenhouse Effect

The atmospheric phenomenon where solar radiation passes through the atmosphere, is absorbed by greenhouse gases, and is reradiated in all directions, elevating global temperatures.

Greenhouse Gases

Any atmospheric gas that absorbs infrared radiation and traps thermal energy within Earth's atmosphere.

Symbiosis

A close, long-term biological interaction between organisms of two different species.

Gene

The fundamental functional and physical unit of heredity.

Trait

An observable physical, biochemical, or behavioral characteristic of an organism.

Alleles

Alternative forms or variants of a specific gene responsible for variations in a given trait.

Gene Pool

The complete collection of all alleles across all individuals comprising a specific population.

Evolution

A change in the frequency of a trait or allele within a population over successive generations.

Natural Selection

The evolutionary mechanism by which organisms better adapted to their environment tend to survive, reproduce, and pass their traits to offspring.

Fitness

The relative ability of an individual to survive and reproduce in its environment, directly reflected by the number of offspring produced.

Adaptation

An inherited feature that becomes prevalent in a population because it confers improved function, survival, or reproductive success.

Population Genetics

The biological field focusing on the study of gene and allele frequencies and dynamics within populations.

Genetic Drift

A random change in allele frequencies within a population resulting from chance events like natural disasters, leading to a surviving gene pool distinct from the original.

Bottleneck Effect

A sharp shift in allele frequency and loss of genetic diversity following a severe, non-selective reduction in population size.

Founders Effect

A change in allele frequencies that occurs when a small, non-representative subgroup of a population migrates away to establish a new colony.

Environmental Selective Pressure

An external environmental condition or factor that causes individuals bearing specific adaptive traits to have greater survival and reproductive success.

Hardy-Weinberg Equilibrium

The theoretical state in which allele frequencies in a population remain stable and non-evolving, requiring a large population, no mutations, random mating, no migration, and no natural selection.

Genetic Equilibrium

A condition in which a population's trait and allele frequencies remain constant from generation to generation without evolving.

Detritivore

A heterotrophic organism that obtains nutritional energy by consuming dead organic matter and decomposing debris.

What is the order of the Phylogenic tree

domain, kingdom, phylum, class, order, family, genus, and species.

whats the trick you can use for the ordering of the Phylogenic tree

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