variation in population size Flashcards
define population size
the number of individuals in a population
the size of a population is eventually determined by_
limiing factors
define carrying capacity
certain population size that can be sustained over a relatively long period and is determined by limiting factors
effect of temperature on a species (eg animals and plants)
decrease in temp: enzymes work more slowly so the metabolicrate is decreased. therefore populations have a smaller carrying capacity
increase in temp- enzymes denaturing, reduces carrying capacity
how can the carrying capacity of warm blooded animals still decrease even though they can maintain a constant body temp
when temp is higher than optimum temp, they expend more energy trying to maintain normal body temp therefore less energy for growth so they mature more slowly and reproductive rate slows. carrying capacity decreases.
abiotic limiting factors
light, temperature, pH, water and humidity
the influence of abiotic on plant populations
species X and Y can tolerate different temp and different pHs. they avoid direct competition by occupying different niches= niche separation
identify the difference between a habitat and a niche
a habitat is the place where a community of organisms live.
a niche refers to not only the place where an organism lives but also what it does there- includes all the abiotic and biotic conditions for an organism to survive and reproduce
define niche
the abiotic and biotic resources used by a population in its habitatto survive and reproduce
define interspecific competition
between members of 2 DIFFERENT species
define intraspecific competition
between members of SAME species
what is the competitive exclusion principle
when theecological niche of 2 species are so similar that they compete for the same limited resources, they cannot coexist indefinitely
define realised niche
niche that is restricted by the prescence of a competitor
define fundamental niche
niche that would occur without the competitor
can 2 species share the same ecological niche?
no.
2 species cant share the same ecological niche but individuals of the same species may have diff niches
