Population Growth and Resource Availability - AP Environmental Science

1. What happens to a population when birth rates equal death rates?

   Population size remains stable. Zero population growth occurs when births equal deaths.

2. Identify one example of a density-dependent factor.

   Competition for resources. Effect intensifies as population density increases.

3. Which factor is considered an abiotic limiting factor?

   Water availability. Non-living environmental factor that constrains population size.

4. Explain the concept of demographic transition.

   Shift from high birth and death rates to low rates as a country develops. Economic development typically reduces birth and death rates over time.

5. What is the significance of $e$ in growth equations?

   Base of the natural logarithm, used in continuous growth models. Mathematical constant approximately 2.718 for exponential functions.

6. Name a human activity that affects carrying capacity.

   Agriculture. Human activities can increase or decrease environmental carrying capacity.

7. Identify a renewable resource that can affect carrying capacity.

   Forests. Renewable resources can sustainably support populations when managed properly.

8. Define carrying capacity.

   Carrying capacity is the maximum population size an environment can sustain. Environmental limit determined by resource availability and space constraints.

9. What is the effect of low mortality rates on population size?

   Increases population size. Fewer deaths means more individuals survive to reproduce.

10. Which factor is an example of environmental resistance?

    Predation. Density-dependent factor that removes individuals from population.

11. Identify the shape of a logistic growth curve.

    An S-shaped curve. Initial slow growth accelerates, then levels off at carrying capacity.

12. Identify one effect of resource abundance on populations.

    Supports population growth. Adequate resources reduce environmental resistance and mortality.

13. What is the effect of high birth rates on population size?

    Increases population size. More births than deaths leads to population expansion.

14. Which model represents human population growth?

    Exponential growth model. Humans show J-shaped growth despite resource limitations.

15. How does urbanization affect population growth?

    Often decreases birth rates. Urban living typically reduces family size and birth rates.

16. What does a J-shaped curve indicate in population studies?

    Exponential growth. Characteristic shape of unlimited exponential population growth.

17. Which type of population growth is density-independent?

    Exponential growth. Growth rate remains constant regardless of population density.

18. State the equation for per capita growth rate.

    $r = \frac{\text{births} - \text{deaths}}{N}$. Measures net change in population size per individual.

19. What is the impact of resource availability on population growth?

    Limited resources slow population growth. Scarcity creates competition and density-dependent factors that reduce growth rates.

20. What is the result of high emigration rates on population size?

    Decreases population size. Net loss of individuals reduces total population size.

21. What is a limiting factor in population growth?

    A resource that restricts population size. Environmental factor that prevents populations from reaching biotic potential.

22. What is the significance of $t$ in growth equations?

    Time period over which growth is measured. Time variable represents duration of growth or observation period.

23. Explain what $r$ represents in population equations.

    Intrinsic rate of increase. Maximum per capita growth rate under ideal conditions.

24. Describe the role of disease in population dynamics.

    Acts as a density-dependent limiting factor. Spreads faster in dense populations, reducing survival rates.

25. State the formula for logistic population growth.

    $N_t = \frac{K N_0}{N_0 + (K - N_0)e^{-rt}}$. Accounts for environmental resistance that slows growth near carrying capacity.

26. Identify one consequence of exceeding carrying capacity.

    Population decline or collapse. Overshoot leads to resource depletion and population crash.

27. What is the main feature of a population experiencing logistic growth?

    Population growth slows as it approaches carrying capacity. Environmental resistance increases as population approaches $K$.

28. Define the term 'biotic potential'.

    Maximum reproductive capacity under optimal conditions. Theoretical maximum growth rate without environmental limitations.

29. What is the difference between biotic and abiotic factors?

    Biotic factors are living; abiotic are non-living elements. Distinguishes between living organisms and physical environmental components.

30. What is the formula for exponential population growth?

    $N_t = N_0 e^{rt}$. Models unlimited growth where population multiplies by constant factor over time.

31. What is the main characteristic of a population in the stationary phase?

    Growth rate is zero; population size stabilizes. Population has reached carrying capacity with balanced birth and death rates.

32. Identify a factor that can lower biotic potential.

    Limited food supply. Resource scarcity reduces reproductive success and survival.

33. What does the variable $K$ represent in population modeling?

    Carrying capacity. Maximum sustainable population size for a given environment.

34. Define environmental resistance.

    Factors that limit population growth. Combined biotic and abiotic factors that limit population growth.

35. Which model assumes unlimited resources?

    Exponential growth model. Assumes infinite resources and no environmental resistance to growth.

36. What is the role of competition in population dynamics?

    Limits population size through resource scarcity. Intraspecific competition intensifies as resources become scarce.

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