Ecology 203. Exam II. Name _________________________

Short answer. Answer FOUR of the following for 10 points each. Place answers in your bluebook. Make sure you identify which questions you are answering. Please consider the amount of time; your answers should be short but complete. If the question seems too easy your answer will probably be incomplete.

  1. Discuss the differences between r-selected and K-selected species.
  2. Discuss abiotic extrinsic regulation of a population with an example.
  3. Describe two ways in which species become extinct.
  4. Graph the Allee effect as dN/dt as a function of population size. Analyze the graph and discuss.
  5. Briefly discuss the characteristics and purpose of optimal foraging theory.
  6. Hamilton and May’s 1977 paper on dispersal concluded that v = 1/(2-p), where v is the proportion of individuals that disperse and p is the fraction of offspring that successfully arrive at a new site. What is the significance of this result?
  7. Discuss why Thomson’s gazelles stot.
  8. Discuss the "herbivore optimization hypothesis." Be sure to supply a graph.
  9. Discuss the interaction of mycchorizae with their plant host on control and fertilized soils, as described in lecture and your book.
  10. Discuss the concept of "niche."
  11. Describe how you might go about mapping a community food web.
  12. Discuss two patterns (facts) of species diversity on the Earth.

 

Define FOUR of these in your blue book. (5 points each)

  1. Key factor analysis
  2. Metapopulation
  3. Population model
  4. Complex adaptive system
  5. Exaptation
  6. Keystone predator
  7. Community development

Discussing and interpreting graphs. Choose TWO questions. 15 points each.

  1. Create two graphs depicting predator-prey interactions. One should be predators graphed as a function of prey; the other graph showing the numbers of predators and prey as functions of time. Discuss the assumptions underlying the model. Remember to include all equilibria and label them as stable or unstable.
  2. Graph the theory of island biogeography, discuss the assumptions, and discuss its application to conservation biology.
  3. Analyze the following graph depicting zero isoclines for the competition between species N1 and N2. Include the equilibrium/equilibria and whether it is/they are stable or unstable. Beside the graph briefly mention the assumptions.

 

 

 

True/False. Answer FIVE of the six. (2 points each)

____ Successful invaders disrupt ecological processes.

____ Plants, because they are stationary, are not able to defend themselves against herbivore attack.

____ Mycorrhizae were seen in the book and lecture to reduce the number of inflorescences when the soil was fertilized for several years.

____ With the advent of modern medicine only about 1 million people die each year of infectious diseases.

____ Diseases begin their interaction as parasites and eventually evolve to a state of benign coexistence, occasionally approaching a mutualistic relationship with their hosts.

____ Predators usually follow a Type I function response, eating prey in proportion to the prey’s abundance.