9.2 Population Growth Flashcards
BR, DR & MR are affected by:
Food supply
Ability to reproduce
Predation
Disease
The size of a population depends upon its:
Birth rate
Death rate
Migration into and out of the pop.
In a stable ecosystem where these factors are balanced, the size of the population remains:
Fairly constant
Limiting factors keep the population at the :
Maximum size that can be sustained by the ecosystem
The maximum size that can be sustained by the ecosystem is known as the:
Carrying capacity
Limiting factors that determine the carrying capacity are collectively called:
Environmental resistance
9 Factors that increase the carrying capacity:
Plentiful food Adequate water supply Favourable light intensity & duration Fewer predators Effective means of avoiding predation Effective means of resisting disease Favourable climatic conditions Constant abiotic conditions High reproductive rate
9 Factors that decrease the carrying capacity:
Inadequate food supply Inadequate water supply Inappropriate light density & duration Increased number of predators Ineffective means of avoiding predators Inability to resist disease Unfavourable climatic conditions Fluctuating abiotic conditions Low reproductive rate
2 types of limiting factor:
Density-dependent
Density-independent
Density-dependent factors have effects that:
Depend on the population density
They have a greater effect when the population is large and individuals are living close together
Usual biotic ones
Density-independent factors are:
Abiotic factors
Have similar effects regardless of the population size/density
Density-dependent limiting factors result in:
Competition between individuals for limited resources, such as water, food and territories
If the competition is between members of different species it is called:
Interspecific competition
If the competition is for limited resources between members of the same species it is:
Intraspecific competition
Natural selection can change the frequency of:
Alleles within a population
