CHAPTER 40: POPULATION ECOLOGY AND THE DISTRIBUTION OF ORGANISMS
1. Define the following terms:
a. Abiotic
b. Biotic
Concept 40.3 – Interactions between organisms and the environment limit the distribution of
species.
2. Explain how each of the following limit the distribution of species.
a. Dispersal
b. Biotic factors
c. Abiotic factors
i. Temperature
ii. Water and Oxygen
iii. Salanity
iv. Sunlight
v. Rocks and Soil
Concept 40.4 – Biotic and abiotic factors affect population density, dispersion, and
demographics.
3. What is the difference between density and dispersion?
4. What four factors affect the density of a population?
5. List the dispersion pattern shown by each population in the figure below. What do the
dispersion patterns tell us about the population and its interactions?
6. Define the following terms.
a. Demography
b. Life table
c. Cohort
7. Survivorship curves show patterns of survival. In general terms, survivorship curves can be
classified into three types. Using the figure below, label and explain the three idealized
survivorship patterns.
Concept 40.5 – The exponential and logistic models describe the growth of populations.
8. The equation for determining changes in population size is shown below. What does each
letter represents in the equation?
9. What does per capita change in population represent?
10. What is exponential population growth?
11. Write and explain the equation for exponential population growth.
12. This graph compares growth in a population with r = 1.0 (gray curve) to growth in a
population with r = 0.5 (black curve). How many generations does it take each of these
populations to reach a size of 1,500 individuals?
13. What is carrying capacity?
14. What is logistic population growth?
15. Write and explain the equation for logistic population growth.
16. Label the graph below. What does it tell you and why? How does “K” fit into all of this?
Concept 40.6 – Population dynamics are influenced strongly by life history traits and
population density.
17. In terms of population dynamics, name two things that natural selection favors.
18. Define life history and list three main variables it entails.
19. Compare and contrast K-selection and r-selection.
20. What is the difference between density-dependent and density-independent?
21. Population dynamics is the study of how complex interactions between biotic and abiotic
factors influence variations in population size. Explain how each factor in the table below
affect population size.
Competition for Resources
Toxic Wastes
Predation
Territoriality
Disease
Intrinsic Factors