24.1 population size Flashcards
1
Q
what are the 3 phases of the population growth curve
A
- slow growth (birth rate>death rate so population increases)
- rapid growth (breeding individuals increase so population multiplies exponentially)
- stable state (external constraints prevent further population growth)
2
Q
what are some limiting factors of population growth
A
- competition for resources
- build-up of toxic by-products of metabolism
- disease
3
Q
define carrying capacity
A
maximum population size that an environment can support
4
Q
what is immigration
A
individuals move into a particular area and increase population size
5
Q
what is emigration
A
individuals move away from a particular area and decrease population size
6
Q
what are density independent factors
A
factors that have an effect on the whole population (regardless of size) and dramatically change the size
e.g. earthquakes/fires/volcanic eruptions/storms
7
Q
examples of abiotic limiting factors (6)
A
- temperature
- light
- water availability
- light availability
- humidity
- pH
8
Q
examples of biotic limiting factors (3)
A
- predators
- disease
- competition
