APES Unit 1 Study Guide: Populations and Toxicology
1. What is the difference between population size and population density?
2. Describe the three different types of population dispersions: Clumped, uniform, and
random.
3. When is a population said to have a high population momentum?
4. Describe the different characteristics of r-strategists and k-strategists.
5. How does environmental resistance influence populations?
6. Explain carrying capacity and how it may influence populations.
7. Draw an exponential growth curve and a logistic growth curve below. Explain what
these different graphs say about the population and the available resources.
8. Why does overshoot take place?
9. Describe the difference between density independent and density dependent population
controls and provide an example for each.
10. Define total fertility rate. How do these differ between developed and developing
countries?
11. What are at least 3 reasons total fertility rates are high in developing nations?
12. Although U.S. fertility rate is decreasing, name two reasons why the population will
continue to increase more than any other developed nation.
13. What do survivorship curves tell us about a population?
14. Describe the differences between the late loss curve, constant loss curve, and the early
loss curve. What do these curves tell us about a population, and what are some specific
species which these curves may represent.
15. If Thailand’s population growth rate is 7% in 2000, when will it’s population double?
(use the rule of 70)
16. List three ways in which population growth may be decreased (other than sterilization or
child bearing laws).
17. What are some issues that populations that have more post-reproductive individuals than
others, such as China and Thailand, face?
18. What is demographic transition?
19. Describe the pre-industrial stage, transitional stage, industrial stage, and post-industrial
stage. Provide a graph as it relates to population.
20. Using the growth rate formula calculate the growth rate of a country with a CBR of 15, a
CDR of 10, an immigration rate of 5, and an emigration rate of 2.
21. Explain why our perceived risks may be inaccurate compared our actual risks.
22. What are the different clinical endpoints in terms of toxicity? Describe each.
23. Differentiate between LD50 and LC50. Include how they are measured.
24. What are the 3 primary routes in which organisms are exposed to pesticides?
25. Differentiate between acute, chronic, and subchronic exposure.
26. When is it appropriate to use the following signal words: caution, warning, and danger?
27. When is a substance legally deemed a poison?
28. Describe the unit of toxicity mg/kg.
29. Define a pest.
30. Desribe the following terms in relation to pesticides: broad-spectrum agents, narrowspectrum agents, persistence, synergism, and threshold level of toxicity.
31. What did farmers use prior to the 1950s as weapons against pests?
32. Describe three reasons one may support the use of biocides, and vice versa.
33. What is the pesticide treadmill?
34. Review several of the toxins discussed in class, their side effects, and how they get into
our environment.
35. What are the main reasons in which DDT was used?
36. Describe the life cycle of malaria and of the West Nile Disease.
37. When new diseases are appearing, what are the first steps scientists must take in order to
control the spreading?
38. Describe the persistence of DDT.
39. What were some negative side effects being seen in ecosystems as result of DDT usage?
There are several.
40. Who is Rachel Carson and how has she contributed to environmental science?
41. Why did it take several years for DDT to be banned in the United States? Are we still
linked to DDT? Explain.
42. Explain biomagnification.
43. Why are chlorinated hydrocarbons so terrible for the environment?
44. What does the ozone molecules in the stratosphere do for us?
45. Explain how ozone is naturally formed.
46. What is integrated pest management?
47. What does FIFRA require?
48. What are the different types of waste?
49. What does it take for a substance to be considered “hazardous waste”?
50. Describe the different ways in which we may manage hazardous waste. These include
hazardous waste detoxification, bioremediation, phytoremediation, incineration, land
disposal, surface impoundments, landfills, and export.
51. Where does the majority of our hazardous waste end up?
52. What are dioxins and what are some side effects caused by dioxins?
53. What is the Superfund Act and how does it relate to Love Canal, New York?