6.3.2 (a) factors affecting population size Flashcards
phase 1 of population growth
period of slow growth
birth rate is higher than the death rate
therefore the population increases in size
phase 2 of population growth
period of rapid growth
number of breeding individuals increase
population size multiplies exponentially
phase 3 of population growth
external constraints stunts population growth
birth rate and death rate are kinda equal
when does growth occur?
when conditions are ideal and optimum
growth curve diagram
what are the 2 types of limiting factors of population growth?
biotic
abiotic
what are biotic factors?
living factors
examples of biotic factors
predators
disease
competition
what are abiotic factors?
non-living factors
examples of abiotic factors
temperature
light
pH
water availability
humidity
what is carrying capacity?
maximum population size an environment can support
what are the 2 types of migration?
immigration
emigration
what is immigration?
movement of individual organisms into an area which increases the population size
what is emigration?
movement of individual organisms out of an area which decreases the population size
what are density independent factors?
factors which have an effect on the whole population size
they can eliminate an entire population
