Section 1: Everything Is Connected
1. What is one way alligators and other organisms interact?
a. Alligators dig holes. c. Alligators escape from heat.
b. Alligators swim. d. Fish use holes dug by alligators.
STUDYING THE WEB OF LIFE
2. What is ecology?
3. What is the biotic part of the environment?
4. What is the abiotic part of the environment?
For each word listed, write whether it is from the biotic or abiotic part of the environment.
Chapter 18: Interactions of Living Things 4
5. Alligator ______
6. Gar ______
7. Temperature ______
8. Water ______
9. Plants ______
10. Rocks ______
Chapter 18: Interactions of Living Things 4
Put the five levels of environmental organization in order from smallest to largest. Write the appropriate number in the space provided.
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11. Population ______
12. Biosphere ______
13. Individual organism ______
14. Ecosystem ______
15. Community ______
Chapter 18: Interactions of Living Things 4
16. A group of seaside sparrows competing for food, nesting space, and mates in a salt marsh is an example of the ______level of environmental organization.
17. List four species in the salt marsh community.
18. List three ways that species in the salt marsh community use cordgrass.
19. An ecosystem is made up of a community of organisms and the ______parts of the environment, such as temperature, soil, and water.
20. The ocean, the air, and all areas of Earth where life is are all parts of the ______level of organization.
Section 2: Living Things Need Energy
1. To survive, living things need
a. grasslands. b. energy. c. clothing. d. species.
THE ENERGY CONNECTION
2. What three groups can animals be divided into based on how they get energy?
3. Organisms that use sunlight directly to make food are called ______.
4. Producers use a process called ______to make food.
5. Herbivores, carnivores, and omnivores that eat other organisms are known as ______.
6. A consumer that eats only plants is a(n) ______.
7. A consumer that eats only animals is a(n) ______.
8. A consumer that eats both plants and animals is a(n) ______.
9. An example of a herbivore is a(n) ______.
10. An example of an omnivore is a(n) ______.
11. Omnivores that eat dead plants and animals are called ______.
12. Organisms that break down dead organisms to get energy are called ______.
13. List two decomposers.
14. A simple diagram that shows how energy in food flows from one organism to another is a(n) ______.
15. A food chain does not show energy connections in nature as accurately as a food ______does.
16. In food webs and food chains, does the arrow point toward the plant or animal doing the eating or the one that is eaten?
17. List the two main food webs on Earth.
18. Why isn’t all of the energy that grass gets from sunlight passed on to the prairie dogs that eat the grass?
19. The diagram that shows an ecosystem’s loss of energy at each level of the food chain is known as ______.
WOLVES AND THE ENERGY PYRAMID
20. When gray wolves were wiped out as the wilderness was settled, what happened to the grass and elk in some areas?
21. What effect does the U.S. Fish and Wildlife Service think the return of wolves will have in Yellowstone National Park?
22. Why are ranchers near Yellowstone worried about wolves returning?
23. How have three populations of organisms changed since the reestablishment of wolves in Yellowstone National Park?
Section 3: Types of Interactions
1. In a natural community, population sizes vary because
a. the populations are not affected by each other.
b. the populations all affect one another.
c. individuals in the populations decide to have big families.
d. the populations are able to grow without stopping.
INTERACTIONS WITH THE ENVIRONMENT
2. When a frog lays hundreds of eggs in a small pond, what happens to the population of frogs in the pond? Explain your answer.
3. A resource so scarce that it limits the size of a population is called a(n)
4. In what way can food become a limiting factor?
5. The largest population that an environment can support is called its
6. What happens when a population grows larger than its carrying capacity?
INTERACTIONS BETWEEN ORGANISMS
7. Ecologists have listed four main ways that species and individuals affect other—competition, ______and prey, symbiosis, and coevolution.
COMPETITION
8. When two or more individuals or populations try to use the same resource, it is called
9. Give an example of competition between individuals within a population and of competition between populations.
PREDATORS AND PREY
10. What word is used for an organism that eats another organism?
a. predator b. carrier c. competitor d. prey
11. What word is used for an organism that is eaten?
a. predator b. carrier c. competitor d. prey
12. List two adaptations predators use to catch prey.
13. List two ways prey have adapted to avoid predators.
14. Give two examples of animals using defensive chemicals against predators.
15. How can being bright red, yellow, or orange help an animal avoid predators?
SYMBIOSIS
16. A close, long-term association between two or more species is called
a. symbiosis. b. defensive chemicals c. predator adaptations. d. camouflage
17. What are the three types of symbiosis?
18. Both organisms benefit in the type of symbiosis called ______.
19. When one organism benefits and the other is unaffected, the symbiotic relationship is called ______.
20. A symbiotic relationship in which one organism benefits and the other is harmed is called ______.
21. In parasitism, the organism that benefits is called the ______.
22. The organism that is harmed by a parasite is called the ______.
23. Do most parasites kill their hosts? Why or why not?
COEVOLUTION
24. What name is given to a long-term change that takes place in two species because of their close interactions with one another? Give an example.
25. Describe an example of coevolution between a flower and its pollinator.
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