2.2 Flashcards
What factors determine population growth?
Birth rates, death rates, immigration, and emigration.
What happens to a population if birth rates and immigration are higher than death rates and emigration?
The population will grow.
What happens if death rates and emigration exceed birth rates and immigration?
The population will decrease.
How do you sketch a basic exponential growth graph?
It starts slow and curves upward, forming a “J-shaped” curve.
How do you sketch a basic logistic growth graph?
It starts like exponential growth but levels off into an “S-shaped” curve as the population reaches carrying capacity (K).
In exponential growth, where is population growth highest?
Growth is highest at the end of the curve, when the population is large.
In logistic growth, where is population growth highest?
Growth is highest in the middle of the curve, before reaching the carrying capacity (K).
What does the variable “N” represent in growth models?
Current population size.
What does “N₀” stand for in population growth models?
Initial population size.
What does “r” represent in population growth equations?
The per capita growth rate (birth rate minus death rate).
What does “t” stand for in the population growth model?
Time.
What does “K” represent in the logistic growth model?
Carrying capacity, or the maximum population size the environment can sustain.
What does “dN/dt” mean in population growth equations?
The rate of change in population size over time.
What are density-dependent limiting factors? Give examples.
Factors that increase in effect as population density rises, like competition for food, predation, and disease.
What are density-independent limiting factors? Give examples.
Factors that affect populations regardless of density, such as natural disasters, temperature, and pollution.
