Environmental Science - Ch 3 Flashcards
Classification of Organisms (From Top to Bottom)
Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species
Species
Taxonomic classification of a population of organisms whose members can interbreed and produce fertile offspring
Population
A group of a particular species that live in the same geographic area
Evolution
Change in population over time due to alterations in genetic material (DNA), resulting in new behavioral and physical characteristics
Natural Selection
A process where inherited characteristics that enhance survival are passed along to future generations more frequently than those characteristics that do not enhance survival
Survival of the Fittest
Organisms who are better adapted to the environment will be the ones who survive and successfully reproduce. They will pass those adaptions on to their offspring.
Adaption
Characteristics that increase reproductive success will spread over time throughout the population.
Genes
Segments of DNA that carry information that determines physical traits and functions.
Mutation
A mistake that occurs during replication.
Speciation
The process by which new species are generated
Phylogenetic Tree
Diagram that depicts the evolutionary relationships between organisms
Ecology
Study of the interactions among organisms and with their environment
Organism
Single living thing
Community
All of the populations of different species that live and interact in an area
Ecosystems
Communities and all of the abiotic parts of the environment
Ecosystem Ecology
Studies the flow of energy and nutrients between the living and nonliving parts of the community
Biosphere
The sum total of all living things and habitats on Earth
Landscape Ecology
Examines how ecosystems, communities and populations are distributed across the Earth
Habitat
The environment in which each organism lives
Population Size
The number of organisms in an area at a given time
Population Density
The number of individuals per unit area
Population Distribution
The spatial arrangement of organisms within an area
Random Distribution
No particular pattern
Uniform Distribution
Individuals spaced evenly throughout the area
Clumped Distribution
Individuals concentrate in certain areas
Sex Ratio
Proportions of males to females in a population
Age Structure
Number of individuals of different ages in a population
Natality
Births within a population
Mortality
Deaths within a population
Immigration
Arrival of individuals from outside the population
Emigration
Departure of individuals from the population
Rate of Natural Increase
Birth rate - Death rate
Population Growth Rate
The effects of immigration and emigration (Birth rate - Death rate) + (Immigration rate - Emigration rate)
Survivorship Curves
Graphs that show the proportion of a population that survives from one age to the next
Type III Survivorship Curves
Occur when many offspring are produced but there is little parental investment
Type II Survivorship Curves
Mortality occurs at approximately the same rate throughout the life cycle
Type I Survivorship Curves
Significant investment in parental care. Survivorship rate of the young is high.
Exponential Growth
Occurs when a population is small, competition is minimal, and environmental conditions are ideal
Carrying Capacity
The maximum population size of a species that an environment can sustain
Logistical Growth
Population growth slows as it reaches carrying capacity
Density Dependent Factors
Rise and fall with the population density
Examples of Density Dependent Factors
Predators, Diseases
Density Independent Factors
Unaffected by population density
Examples of Density Independent Factors
Temperature extremes, catastrophic natural disasters
