bio test chapter 2 Flashcards
The total number of individuals in a population
population size
defined as the number of individual organisms in a given area or volume
population density
n/a or n/v
equation for population density
used for stationary organisms such as plants. are useful when the density of a species is low or when individual organisms are very large.
transect
they are done by first choosing random locations at each site and a blank of known size is marked out. The number of individuals of a species within the blank is counted.
quadrat
A meathod in which animals are captured, marked with a tag, collar, or band, released and than captured at a later time to determine an estimate of population size.
mark and recapture
members of a population are found in close proximity to each other in various groups within their habitat.
clumped distribution
found in artificial populations, such as plants growing in orchards or agricultural feilds in which individuals are evenly spaced over a defined area.
uniform distribution
this can occur when resources are very abundant and population members do not have to compete with one another or group together for survival. individuals or parts of organisms are distributed throughout a suitable habitat with no identifiable pattern.
random distribution
the movement of individuals into a population
immigration
the movement of individuals out of a population
emigration
the ratio of the number of births to the size of the population; birth rate
natality
the state of being subject to death
mortality
N=(B+I) - (D+E)
calculating population size
the study of populations, especially population size, density, age structure, and growth.
demography
s-shaped growth curve
logistic
j-shaped growth curve
exponential
in the beginning, the growth of population is slow, since there is only a few individuals to reproduce
lag phase
when the birth rate is much higher than the death rate, so the population will increase rapidly
exponential phase
when the birth rate and death rate are equivalent
equilibrium
the teoretical maximum population size that the enviroment can sustain over an extended period of time
carrying capacity
species that have a short life spand and an early reproductive age, they produce large broods of offspring that receive little or no parental care.
r-growth strategies
they have few offspring per reproductive cycle and one or both parents care for the offspring when young. The offspring take relatively long to mature and reach reproductive age and they live a relatively long time
k-growth strategies
