Population Notes Unit 4 Flashcards
What is a population?
A population is a group of organisms of the same species that live in a specific that live in a specific area and interbreed.
What is density?
number of individuls of the same species in that live in a given unit of area
what is dispersion
the pattern of distribution of organisms in a population
what are the three types of dispersion
even, clumped, and random
why do species tend to clump
they cluster where resources are available, groups have better chance of finding resources, protection, and packs allow to capture prey
what is the formula for population size (growth rate)
births-deaths
what is teh formula for population change
(births + immigration) - (deaths + emigration)
what is range of tolerance
variations in physical and chemical environment that a species can survive
what are limiting factors
factors that determine the viability of life
what is carrying capacity
max population size given habitat can sustain
what is the symbol for carrying capacity
K
what are zones of stress
zone that occurs above or below optimum levels
what is the law of limiting factors
quanitities of any single factor above or below optimum levels necessary for growth
what is exponential growth
as a population gets larger, it grows faster
what is the shape of exponential growth
J
what is linear growth
straight line on graph that shows slow and steady growth
what is logisitic growth
S shaped graph that shows limits on growth rate
what is carrying capacity
the number of organisms of one species that an environment can support
what is an irruptive population change
population surge followed by a crash
what is a cyclic fluctuation
top-down population regulation or bottom-up population regulation
what is irregular population change
population change that has no pattern
what are 4 density dependent population controls
predation, parasitism, infectios disease, competition for resources
what happens when a population goes over its carrying capacity
it can crash
what is intraspecific competition
competition between members of the same species
what is interspecific competition
competition that happens between different species
what is biotic potential
fastes rate at which populations can grow
what is reproductive potential
maximum number of offspring that a given organism can produce
what is a k-selected species
reproduce later in life, not many offspring, long time to maturity, more parental care
what is an r-selected species
many offspring, little to no parental care, massive deaths of offspring
what is a type I survivorship curve
convex, most individuals live to adulthood
what is a type 2 survivorship curve
straight line, individuals chance of dying is independent of its age
what is a type 3 survivorship curve
concave curve, few individuals live to adulthood, chance of dying decreases with age
what is the formula for growthrate
birthrate-deathrate
what occurs in the pre-industrial stage
birth rates and death rates both high
what happens during the transitional stage
death rates decline due to increased food production and good medical care
what happens in the industrial stage
birth rate declines due to increase opportunities for women and access to birth control
what happens in the post-industrial stage
birth rates and death rates are low
what does a broad based pyramid graph represent
high birth rates with a low life expectancy
what is the formula for the rule of 70
70/growthrate
what is the formula for rate of natural increase
births per 1000 - deaths
what is the percent error formula
absolute value of accepted value minus estimated over accepted value
what is the formula for the Lincoln index
N= (n1 x n2)/m
what does N represent in the lincoln index
total population
what does n1 represent in the index
number of animals captured on first day
what does n2 represent
number of animals recaptured
what does m represent in the index
number of marked animals recaptured
what is the formula for population density
population/area
what is the birth rate formula
births/total population
what is the formula for percent change
new value - original value / original
how do you estimate population size
find average number of individuals in certain plots and divide the average by the total number of plots
