Section: What Is an Ecosystem?
In the space provided, write the letter of the description that best matches the term or phrase.
1. biome 2. habitat 3. community 4. ecosystem 5. succession 6. biodiversity
In the space provided, write the letter of
the term or phrase that best completes
each statement or best answers each question.
7. An ecosystem is defined by the
a. organisms living in a particular area.
b. climate of the region.
c. community and physical aspects of the area.
d. pioneer species that occupy the area.
8. A measure of how many different species live in an ecosystem is its a. ecology.
b. biodiversity.
c. biology.
d. abiotic factor.
9. A typical organism that might occupy a forest in the southeastern United States is a a. cactus.
b. wolf.
c. deer.
d. polar bear.
a.the place where a population of a species lives
b.a community and all of the physical aspects of its habitat
c.the variety of organisms in an area d.the replacement of one kind of
community by another at a single place over time
e.the different species that live in a habitat f.a large region characterized by a climate and its specific plant and animal
communities
10. In which area would you expect to find the most biodiversity?
a. a square yard of forest floor b. a square yard of desert sand c. the surface of a mountain stream
d. a rock recently exposed by a retreating glacier 11. An ecosystem includes which of the following?
a. microscopic organisms c. weather conditions b. large mammals d. All of the above
12. Which of the following can be considered an entire ecosystem?
a. a small patch of farmland b. the underside of a large rock c. a stream flowing through a pasture d. All of the above
13. An example of a biotic factor in an ecosystem is a. an active volcano.
b. the number of competing species.
c. a river that floods frequently.
d. the intensity of sunlight in summer.
Read each question, and write your answer in the space provided.
14. What is meant by the term pioneer species?
15. Why is Glacier Bay, Alaska, an example of how ecosystems change over time?
16. What is the primary difference between a freshwater ecosystem and a marine ecosystem?
Section: Energy Flow in Ecosystems
In the space provided, explain how the terms in each pair differ in meaning.
1. producers, consumers
2. trophic level, food chain
3. herbivores, carnivores
4. omnivores, decomposers
In the space provided, write the letter of the description that best matches the term or phrase.
5. omnivores 6. herbivores 7. producers 8. energy pyramid 9. decomposers 10. consumers 11. carnivores 12. food web 13. food chain
Complete each statement by writing the correct term or phrase in the space provided.
14. At each trophic level, the energy stored is about ______________________ percent of that stored by the organisms in the level below.
15. A(n) ______________________ ______________________ is a diagram in which each trophic level is represented by a block.
16. Many ecosystems do not have enough energy to support a large population of ______________________.
17. In an ecosystem, energy flows from the ______________________ to producers to consumers.
18. Energy that is not stored or used at each link in a food chain is dissipated as ______________________ into the environment.
19. Big predators on the third or fourth trophic level are rare compared to ______________________
on the second trophic level.
20. Energy may be stored as fat or ______________________.
a.interconnected group of food chains
b.cause decay
c.a path of energy through the trophic levels of an ecosystem d.eat only plants
e.eat only animals
f.organisms that first capture energy g.eat both plants and animals
h.consume plants or other organisms to obtain energy
i.a triangular diagram that shows the movement of energy through an
Section: Cycling of Matter
Read each question, and write your answer in the space provided.
1. What is the source of the energy that drives the water cycle? Explain.
2. Which of the cycles of matter involves the process of percolation?
3. What are the most important substances that pass through the cycles of matter?
Complete each statement by underlining the correct term or phrase in the brackets.
4. The process that returns water to the atmosphere from the surface of lakes and oceans is called [evaporation / transpiration].
5. Water that falls to Earth as rain or snow and seeps into the soil becomes [surface water / ground water].
6. In the living portion of the water cycle, water is taken up by [condensation / the roots of plants].
7. The process by which water evaporates from the leaves of plants is called [respiration / transpiration].
Read each question, and write your answer in the space provided.
8. How does carbon become part of organic molecules?
9. List three ways carbon atoms return to the nonliving part of the carbon cycle.
Complete each statement by writing the correct term or phrase in the space provided.
10. Organisms need nitrogen to build ______________________.
11. Phosphorus is usually present as ______________________ ______________________ in soil and rock.
12. The process of combining nitrogen gas with hydrogen to form ammonia is called ______________________ ______________________.
13. Nitrogen-fixing bacteria use ______________________ to split molecules of nitrogen gas and combine the nitrogen atoms with hydrogen.
In the space provided, write the letter of the term or phrase that best completes the statement or answers the question.
14. All of the following are examples of materials that cycle in ecosystems except a. energy.
b. oxygen.
c. water.
d. nitrogen.
15. Which is one way in which carbon dioxide enters the atmosphere?
a. percolation b. photosynthesis c. combustion d. evaporation
16. Bacteria return nitrogen to the soil by which process?
a. denitrification b. assimilation c. nitrification d. ammonification
Section: Populations
In the space provided, explain how the terms in each pair differ in meaning.
1. exponential growth, logistic growth
2. biotic factors, abiotic factors
Complete each statement by writing the correct term or phrase in the space provided.
3. A(n) ______________________ consists of all the individuals of a species that live together in one place at one time and interbreed.
4. The largest population that an environment can support at any given time is called ______________________ ______________________.
5. The movement of individuals into a population is called ____________________.
6. The movement of individuals out of a population is called ___________________.
7. The type of growth pattern of a population that shows the effects of its carrying capacity is called ______________________ growth.
8. The availability of nesting sites for a population of birds is a density- ______________________ factor in their population growth.
9. Weather events are density-______________________ factors.
10. More children are surviving to adulthood because of the availability of ______________________.
Read each question, and write your answer in the space provided.
11.Why is size an important feature of a population?
12. Why is density an important feature of a population?
13. What are the two major types of population models? Describe them.
Section: Interactions in Communities
In the space provided, write the letter of the description that best matches each term.
1. predation 2. commensalism
3. coevolution 4. mutualism 5. symbiosis 6. parasitism 7. herbivory 8. host 9. prey
Complete each statement by writing the correct term in the space provided.
10. The evolution of predators to be more cunning and prey to be faster runners is an example of ______________________.
11. The relationship between dogs and fleas is an example of ______________________.
12. Orchids growing on the trunks of trees are an example of ______________________.
a. a relationship in which both species benefit b. one organisms feeds and lives on another
specific organism
c. an organism that provides food and a place to live for a parasite
d. one organisms kills another for food e. the act of eating plants
f. back-and-forth evolutionary adjustment between two species that interact
g. an organism that is hunted and eaten by a predator
h. a relationship in which two species live in a close association with each other
i. a relationship in which one species is helped and the other is neither harmed nor helped
Complete each statement by underlining the correct term in the brackets.
13. In the relationship between lions and zebras, the lion is the [predator / prey].
14. In a parasite-host relationship, the host is usually [harmed / killed].
15. Some plants have evolved chemical compounds to [attract / discourage] herbivory.
16. The relationship between eels and cleaner fish is an example of [mutualism / commensalism].
17. Evolutionary changes in one species that result in changes in another species is called [mutualism / coevolution].
Read each statement, and write your response in the space provided.
18. Explain how an animal can be both predator and prey.
19. Describe one way a host might defend itself against parasites.
20. Describe the coevolution of monarch butterflies and milkweed.
21. Is the relationship between monarch butterflies and milkweed mutualistic or commensalistic?
Explain your reasoning.
22. Explain why the relationship between orchids and trees is not considered parasitic.
Section: Shaping Communities
In the space provided, write the letter of the description that best matches each term.
1. niche
2. kleptoparasitism
3. competitive exclusion
4. fundamental niche 5. keystone species 6. realized niche 7. competition
Complete each statement by writing the
correct term or phrase in the space provided.
8. A species almost never occupies its entire fundamental niche because of ______________________ with other species.
9. Five species of warbler can live in the same spruce tree without competing by ______________________ ______________________.
10. Interactions between organisms and a high ______________________ help make an ecosystem more resilient.
11. When two species compete for the same resources, the better competitor will eventually eliminate the other species according to the principles of ______________________
______________________.
a.one species eliminates another through competition for resources
b.the entire range of conditions in which an organism could survive
c.a species that is critical to an
ecosystem because it affects the survival of others
d.the role an organism plays within the community
e.biological interaction among
individuals and species that use the same resources
f.the stealing of food from another organism
g the actual niche a species occupies in a
Read each question, and write your answer in the space provided.
12. How does a population of beavers affect a population of fish in the same community?
13. What are three ways that plants have adapted to compete for sunlight?
14. What is the reason that no two similar species can occupy the same niche?
15. Explain how a high biodiversity helps stabilize an ecosystem.
