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23 Cards in this Set

  • Front
  • Back
What are the key elements that determine where an organism lives?
Temperature, Water, Sunlight, and Soil.
What are the two methods of coping with variable environments?
Homeostasis (maintain constant internal conditions) and Conforming (internal conditions vary with environment).
What are the three specific aspects that an organism may change to cope with its environment?
Physiology, Morphology, and Behavior.
What is a population?
A group of individuals that occur together at the same place and time.
What are three particularly important characteristics of population ecology?
Population range (area that it occurs), Pattern of spacing, and Population size.
What are the three types of patterns of spacing in a population? What does each suggest?
Random Spacing (independent of each other and resources, rare), Uniform Spacing (competition for resources), Clumped Spacing (uneven distribution of resources).
What are metapopulations? In what sort of areas do they tend to occur?
Networks of distinct populations that interact by exchanging individuals. Areas with islands or bubbles of suitable habitat separated by unsuitable habitat.
What is a source-sink metapopulation?
A metapopulation with a good habitat with positive growth that sends individuals to cancel negative growth in neighboring bad habitats.
What is demography?
The statistical study of populations.
What are some factors that affect growth rate in a population?
Sex ratio (males to females) and Generation time (time from one's birth to its children's birth).
Define age structure. What are cohorts?
The relative number of individuals in a population's cohorts. Groups of individuals of the same age, each with its own fecundity (birth rate) and mortality (death rate).
How do ecologists assess how populations in nature are changing?
By making life tables.
What is survivorship and a survivorship curve? What are the types of survivorship curves?
The percentage of a population that survives to a given age. A way to express aspects of age distribution on a graph. Type I (die late), Type II (die any time), and Type III (die early).
What is an organism's life history? What is cost of reproduction?
Its complete life cycle. Reduction in future reproductive potential by current reproductive efforts.
What is semelparity? Iteroparity?
The adaptation of focusing all resources on a single reproductive event. The adaptation of spreading resources out and having multiple reproductive events.
What is biotic potential? What is carrying capacity? What is a sigmoidal growth curve?
The rate at which a population grows when no limits are placed on its growth. The amount at which a population stabilizes. The 'S' shaped plot of a population's size rising from a low number to its carrying capacity.
What are density-dependent effects? What is it called when density-dependent effects have positive feedback?
The effects of natural processes that depend on population size (i.e. mortality and birth rate). The Allee effect.
What are density-independent effects?
Situations that affect populations that do not depend on population size (i.e. flood, drought).
What are population cycles? What factors appear to cause them?
Cyclic patterns of increase and decrease in population size over time. Food plants and Predators.
What are K-selected populations? What are r-selected populations?
Populations adapted to reproduce at carrying capacity (effective use of resources). Populations adapted to reproduce below carrying capacity (lots of offspring).
How can a population pyramid project future growth?
A rectangular population pyramid suggests stability, a triangle suggests growth, and an inverted triangle suggests shrinking.
What is the biosphere?
The world's interacting community of living things.
What is an ecological footprint?
The amount of productive land needed to support a typical member of a population.