Shared Flashcard Set

Details

Chapter 53
Ecology Cont.
21
Biology
Undergraduate 2
05/06/2013

Additional Biology Flashcards

 


 

Cards

Term
density
Definition
- the number of individuals per unit area or volume
Term
dispersion
Definition
- the pattern of spacing among individuals within the boundaries of the population
Term
population dynamics
Definition
- study of how complex interactions between biotic and abiotic factors influence variations in population size
Term
immigration
Definition
- coming in
Term
emigration
Definition
- going out
Term
territoriality
Definition
- behavior in which an animal defends a behavior in which an animal defends a bounded physical space against encroachment by other individuals, usually of it's own species (density dependent)
Term
Exponential population growth
Definition
- growth of a population in a ideal, unlmd. environment, represented by a j-curve when pop. size is plotted over time
Term
Carrying capacity
Definition
- maximum population size that can be supported by the available resources, symbolized as k
Term
logistic pop. growth
Definition
- pop. growth that levels off as pop. size approaches carrying capacity
Term
j-shaped graph
Definition
exponential growth
Term
s-shaped graph
Definition
- logistic growth, levels off
Term
k-selected species
Definition
- selection for traits that are sensitive to population density and are favored at high densities, density dependent selection
Term
r-selected species
Definition
- selection for traits that maximize reproductive success in uncrowded environments (low densities) density-independent selection
Term
Density independent
Definition
- a characteristic that is not affected by pop. density ex. birth rate & death rate
Term
density dependent
Definition
- a characteristic that varies with population density ex. a death rate that rises as pop. density rises & a birth rate that falls with rising density
Term
competition
Definition
- competing against another species or within a species (density dependent)
Term
predation
Definition
- interaction between species in which one species the predator, eats the other the prey ( density dependent )
Term
intrinsic factors
Definition
- intinsic physiolgical factors sometimes regulate pop. size. The drop in reproduction at high population density is associated with aggressive interactions and hormonal changes that delay sexual maturation and depress the immune system. In this type of species high density causes a decrease in the birth rate and an increase in the death rate (density dependent)
Term
toxic wastes
Definition
ex. yeasts which is used to convert the carbohydrates into ethanol. The ehtanol that accumulates in the wine is toxic to yeasts and contributes to density dependent regulation of yeast population size of yeast pop size (density dependent)
Term
disease
Definition
density dependent. because the transmission rate of the disease depends on the certain level of crowding in a population
Term
population cycles
Definition
- when pop. fluctuate at unpredictable intervals, and some undergo regular boom-bust cycles
Supporting users have an ad free experience!