Name _____________________ Date: _________
Ecology I
Questions 1-7 refer to the diagram below which shows a complete food web. Each letter represents a species.
1. Why is this considered to be a food web as opposed to a food chain?
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2. What is the highest trophic level in this food web? (What do you call that level, and which letters in the diagram occupy that level?)
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3. What is ultimately driving the energy that allows “O” to be at the bottom of the food web?
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4. Which are the primary consumers?
A. G, S, R, P and F
B. H and P
C. N, L, E and T
D. O
* Give two examples of primary consumers: . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5. How do the nutrients (organic matter, with its stored energy) from the top predators of the food web eventually wind up “recycling” down to the producers again? Who is responsible for that?
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6. If the population of “N” suffered a dramatic decrease due to disease, what would the likely effects on this food web be?
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7. If population “E” were to go extinct, are there other populations that would probably reach extinction as well as a result? If so, which ones?
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8. What is biomass?
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9. What is the difference between biomass and productivity?
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10. List three biotic and three abiotic components of a forest ecosystem.
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11. What is the percentage of energy (or productivity) that is lost on average as you move from one trophic level to the next in a food chain? _____________________
12. If you have a group of organisms living in the same place at the same time and interacting with each other, what is that called? _________________________________________
13. What is a particular type of organism called?
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14. What is a group of individuals of the same species living in the same area at the same time called?
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15. What makes one organism part of one species and another similar organism part of another species? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ………………….
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16. The environment in which a species lives is called?
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17. A community of interdependent organisms and the physical environment in which they inhabit is called?
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18. As disease spreads through a population, numbers fall. As the result of a reduction in contact between individuals, the rate of spread of the disease is reduced. This is followed by a recovery in numbers. This is an example of
A. positive feedback
B. negative feedback
C. demographic transition
D. entropy
19. In as many ways as possible, list how the laws of thermodynamics apply to food chains in an ecosystem.
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20. What kinds of pyramids are able to have an inverted (upside down) shape? Give examples. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ……………
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21. Draw a pyramid of productivity, with 4 trophic levels, and if the producers start with 1600 calories, calculate the values of productivity for the other three trophic levels.
22 .Which of the following is an example of mutualism?
A. Vultures eating a dead antelope
B. A caterpillar eating leaves of a fig tree
C. An insect pollinating an orchid flower
D. A flea living on the skin of a rabbit
23.Which statement best describes the niche of a species in its habitat?
A. The biotic components it requires
B. The biotic and abiotic components it requires
C. The particular place where a species lives
D. The position of a species in the food web
24. Which of the following is most likely to be a parasite?
A. A fungus in the living tissues of a tree
B. A fungus cultivated as a source of food by ants in their nest
C. A fungus growing on the decaying branch of a dead tree
D. A caterpillar consuming the tissue of a living fungus
25. What is the name of the symbiotic relationship in which one species benefits while the other is neither helped nor harmed? ____________________________
26. Give one example of a predator/prey relationship and explain (don’t just “state”) what kind of feedback (positive or negative) this type of interaction has on the populations of the species involved.
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27. Choose the pair of words that most accurately completes the sentence:
“As the niches of two species _________________ in similarity, the competition between the two species _________________.
a.) decrease, intensifies
b.) increase, intensifies
c.) increase, decreases
d.) decrease, stabilizes
28. Resource portioning
a. is crucial for the survival of two species with overlapping niches.
b. serves as a method of reducing intense competition.
c. has been studied extensively with various species of warblers.
d. all of the above.
29. Once a common sight in much of the continent, the Bald Eagle was severely affected in the mid-20th century by a variety of factors, among them the thinning of egg shells attributed to use of the pesticide DDT. Bald Eagles, like many top predators, were especially affected by DDT due to biomagnification. DDT itself was not lethal to the adult bird, but it interfered with the bird's calcium metabolism, making the bird either sterile or unable to lay healthy eggs. Female eagles laid eggs that were too brittle to withstand the weight of a brooding adult, making it nearly impossible for the eggs to hatch. Explain how this scenario exemplifies the idea of biomagnifications.
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30. Compare and contrast interspecific and intraspecific competition. Provide an example of each.
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31. List and describe three ways in which prey have evolved to avoid predators.
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