Chap.6 COPY Flashcards
Definitions (49 cards)
The individuals that belong to the same species and live in a given area at a particular time
Population
All of the populations of organisms within a given area
Community
population ecology
The study of factors that cause populations to increase or decrease
The total number of individuals within a defined area at a given time.
Population size (N)
The number of individuals per unit area at a given time
Population density
A description of how individuals are distributed with respect to one another
Population distribution
The ratio of males to females in a population
Sex ratio
A description of how many individuals fit into particular age categories in a population
Age structure
A resource that a population cannot live without and that occurs in quantities lower than the population would require to increase in size
Limiting resource
A factor that influences an individual’s probability of survival and reproduction in a manner that depends on the size of the population
Density-dependent factor
The limit of how many individuals in a population the environment can sustain
Carrying capacity (K)
A factor that has the same effect on an individual’s probability of survival and the amount of reproduction at any population size
Density-independent factor
Mathematical equations that can be used to predict populaiton size at any moment in time
Population growth models
The number of offspring an individual can produce in a given time period, minus the deaths of the individual or ti’s offspring during the same period.
Population growth rate
The maximum potential for growth of a population under ideal conditions with unlimited resources
Intrinsic growth rate
A growth odel that estimates a population’s future size after a period of time based on the intrinsic growth rate and the number of reproducing individuals currently in the population
Exponential growth model
The curve of the exponential growth model when graphed
J-shaped curve
A growth model that describes a population whose growth is initially exponential, but slows as the population approaches the carrying capacity of the environment
Logistic growth model
The shape of the logistic growth model when graphed
S-shaped curve
When a populatio nbecomes larger than the environment’s carrying capacity
Overshoot
A rapid decline in a population due to death
Die-off
A species with a low intrinsic growth rate that causes the populaiton to increase sloly until it reaches carrying capacity
k-selected species
A species that has a high intrinsic groth rate, which often leads to populaiton overshoots and die-offs
r-selected species
A graph that represents the distinct patterns of species survival as a function of age
Survivorship curve