Ecology Unit Study Guide
Exam Week of 9/17/07
Name:_________________________
Date:______________ Period:_____
1. List several examples of a habitat.
2. A living plant, animal or microbe is what?
3. Define biodiversity.
___________
4. Define ecosystem.
5. With regards to the carbon cycle, what would be the results of the burning and clearing of a
tropical rain forest.
______
______________________________________________________________________
6. What is the ideal pH for freshwater biomes?
7. What activities would have a negative impact on a habitat?
______________________________________________________________________
8. How is the number of organisms in both lakes and ocean ecosystems determined.
__________________________________________________________________
9. Explain how a top predator may increase the diversity of species lower on the food chain.
The next two items refer to the economically valuable forest of the Pacific Northwest.
Douglas fir, cedar and hemlock are the principal trees of the region. Characteristics of each
are as follows.
Douglas Fir
Cedar and Hemlock
Seedlings die in shade
Seedlings grow in the shade
Seedlings grow on ashes
Seedlings do not grow on ashes
Seeds have wings
Seeds are not winged
10. Young cedar trees require what?
11. Which trees would have a survival advantage following a fire?
12. Define nonnative species.
13. Define biological magnification.
14. What is the most common explanation for population growth by a non-native species?
Study the graph below and answer the questions that follow.
15. What does the graph show about the earth’s atmosphere?
16. Most scientists are concerned that global warming is a result of
______________________________________________________________
17. Which environmental factors are looked at when monitoring human pollution?
_______________________________________________________________________
18. The maintenance of a self-sustaining ecosystem requires what?
___
19. Why does each successive feeding level in a pyramid of energy have less biomass? ____
_______________________________________________________________
20. What are examples of plant life at each level of succession starting from new rock?
____________________________________________________________________
____________________________________________________________________
21. According to the graph which one is a carnivore?
22. According to the food web, which of these describes the relationship between the snake and
the chipmunk?
23. Which combination of organisms shows a single food chain in this web?
24. The transition from a tropical rain forest to a grassland is marked by fewer and fewer trees.
This is most likely caused by a decrease in
?
25. Sea otters eat sea urchins. Sea urchins eat kelp, a type of brown algae. What might be the
short-term effect on the ecosystem if great numbers of sea otters were removed from this
environment?
26. What is the ultimate source of energy for the majority of life on Earth?
__
27. Many more species of plants and animals live in a tropical forest than live in a desert. This
difference is most likely due to the fact that, compared to a tropical forest, a desert
______________________________________________________________
28. What part of the ecosystem is not recycled through the Earth’s ecosystems?
______
29. What action by humans has had the
most positive ecological impact on
the environment?
30. According to the graph, the human
population
___________________________
___________________________
31. List several examples of a mutalistic relationship.
32. Natural populations numbers increase and decrease around the carrying capacity when they
reach
33. A group of similar-looking organisms that breed with each other and produce fertile offspring
make up a
34. Rabbits introduced into Australia over 100 years ago have become a serious pest to farmers.
Rabbit populations increased so much that they displaced many native species of plant eaters.
What is the most logical explanation for their increased numbers?
_________________________________________________________
35. What does A stand for in the chart above?
36. Give an example of B in the chart above?
37. What does C stand for in the chart above?
38. If a population grows larger than the carrying capacity of the environment, the
_______________________________________________________________
39. Nutrients move through the biosphere in nutrient or
cycles.
40. As water cycles through the ecosystem, which process returns it to the atmosphere?
41. Local and federal legislation have placed limits on the amount of nitrogen containing fertilizers
to be tolerated in field run-off into a lake. The reason for this legislation is that run-off of the
fertilizers would most likely produce
42. What does each of the letters on the chart represent?
43. Probably the most important factors affecting the distribution of biomes are
____________________________________________________________________
44. Complete burning of plant material returns carbon primarily to what?
45. The action of decomposers in the nitrogen cycle most directly
aids in the_____________________________________
46. What is the role of NO3 in the cycle?
47. In the material cycle above, which processes are represented by letters A and B?
__________________________________________________________
48. Which level of the pyramid represents the largest percentage of available energy?
49. According to the chart, which organisms are the top carnivores in the river ecosystem?
________________________________________
50. According to the chart, if the trout were overfished, which population of organisms would most
likely increase as a direct result?
51. A small, cold creek flows through a dense forest. The trees that line the banks of the creek
provide shade for most of the day. Algae grow well only in the few areas of the creek that
receive direct sunlight for several hours each day. Most of the food energy enters the creek
ecosystem in the form of dead leaves that fall from the trees.
A fire swept through the forest, burning all the leaves but leaving the trees standing. This
greatly increased the amount of direct sunlight reaching the creek, but did not produce more
than the usual amount of erosion. As a result of the fire, which of these most likely increased
in the creek?