Study Guide – Unit 7: Ecology
III. Ecosystems
IV. Describing Populations
V. Nutrient Cycles
Vocabulary:
age pyramid, carrying capacity, commensalism, density-dependent factors,
density-independent factors, exponential growth, keystone species, logistic
growth, mutualism, niche, omnivore, pioneer species, primary succession,
secondary succession, survivorship curve, carbon cycle, nitrogen cycle,
phosphorous cycle
1.
What is an ecosystem?
2.
List the six different levels of organization that ecologists
study, in order from smallest to largest.
3.
What is the difference between photosynthesis and
chemosynthesis?
4.
What is the difference between a food chain and a food
web?
5.
Briefly describe the flow of energy among organisms in an
ecosystem.
6.
7.
8.
What proportion of energy is transferred from one trophic
level to the next in an ecosystem?
Show the following as a food chain: omnivore, autotroph,
herbivore.
Draw an energy pyramid for a five-step food chain. If 100
percent of the energy is available at the first trophic leve,
what percentage of the total energy is available at the
highest trophic level?
12. Based on your knowledge of the carbon cycle, what do you
think might happen if vast areas of forests are cleared?
13. All of life on Earth exists in a region known as the
____________________.
14. Groups of different species that live together in a defined
area make up a(an) ________________________.
15. In the nitrogen cycle, bacteria that live on the roots of plants
a. break down nitrogen compounds into nitrogen gas
b. denitrify nitrogen compounds
c. change nitrogen gas into plant proteins
d. change nitrogen gas into ammonia
16. Which biogeochemical cycle does NOT involve a stage
where the chemical enters the atmosphere?
a. the water cycle
c. the nitrogen cycle
b. the carbon cycle d. the phosphorus cycle
17. What is the definition of ecology?
18. Which group of organisms is always found at the base of a
food chain or web?
19. Why is the transfer of energy and matter in a food chain
only about 10 percent efficient?
20. List two ways in which water enters the atmosphere in the
water cycle.
9.
Where is most of the phosphorus stored in the biosphere?
10. Describe the path of nitrogen through its biogeochemical
cycle.
11. Explain how a nutrient can be a limiting factor in an
ecosystem.
21. Explain the process of nitrogen fixation.
22. What are some of the similarities between the carbon cycle
and the nitrogen cycle?
23. Classify each of the following as a herbivore, carnivore,
omnivore or detritivore:
earthworm
owl
bear
human
cow
24. Which of the following is NOT true about matter in the
biosphere?
a. matter is recycled in the biosphere
b. biogeochemical cycles transform and reuse molecules
c. the total amount of matter decreases over time
d. water and nutrients pass between organisms and the
environment
e. the lack of a specific nutrient can reduce primary
productivity
25. Human activities, such as the burning of fossil fuels, cycle
carbon through the carbon cycle. Which other processes also
participate in the carbon cycle?
I. Biological processes such as photosynthesis
II. Geochemical processes such as the release of gas from
volcanoes
III. Mixed biogeochemical processes such as the formation
of fossil fuels
a. I only
b. II only
d. II and III only
c. I and II only
e. I, II and III
39. The average, year-after-year conditions of temperature and
precipitation within a particular region are its
______________.
40. The greenhouse effect causes an increase in
_____________________.
41. All the biotic and abiotic factors in a pond for a(an)
____________________.
42. A relationship in which one organism is helped and another
organism is neither helped nor hurt is called
_____________________.
43. Natural disturbances, such as fires or hurricanes, can result
in ______________________.
44. List three characteristics that are used to describe a
population.
45. What factors can change a populations size?
26. What effect does latitude have on climate?
46. Define carrying capacity. Give an example.
27. What is the greenhouse effect?
47. List three density dependent factors and three density
independent factors that can limit the growth of a
population.
28. Describe Earth’s three main climate zones.
48. What are age structure diagrams?
29. What are the main factors that determine Earth’s climate?
30. Give an example of an abiotic factor.
49. If a population grows larger than the carrying capacity of its
environment, the
a. death rate may rise
c. death rate may fall
b. birthrate may rise
d. immigration rate may increase
31. What is a niche?
50. Which factors increase the size of a population?
32. What are pioneer species?
51. What are two major global changes affecting the biosphere
today?
33. Name three types of community interactions that can affect
an ecosystem.
34. What is the difference between primary succession and
secondary succession?
35. How is an organism’s niche determined?
36. How are the three types of symbiotic relationships different?
How are they similar?
37. How are biomes classified?
38. What are phytoplankton?
52. A species that enters an environment where it has not lived
before is called a(an)
________________________________.
53. Which of the following is NOT an effect of deforestation?
a. global warming
b. decreased productivity of the ecosystem
c. soil erosion
d. increased ground-water levels
e. mudslides
Suggestions:
•
Begin studying well in advance! Study in small amounts each night. Do
this study guide early!
•
Try to explain concepts to someone else. Write out everything you know on
paper.
•
Complete the review questions in the Techbook. Read the unit again!
•
Review labs & ask for help if needed!
•
Watch the relevant videos for the unit on my YouTube Channel – Biology
playlist.
•
Study vocab cards! Be able to apply the information.