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12.1: Community Interactions

Difficulty Level: At Grade Created by: CK-12

Lesson 12.1: True or False

Name___________________ Class______________ Date________

Write true if the statement is true or false if the statement is false.

_____ 1. All biomes, except a desert, have populations of interacting species.

_____ 2. Camouflage is an adaptation that has evolved through natural selection.

_____ 3. Predation is a relationship in which the prey consumes the predator.

_____ 4. Interspecific competition occurs between members of the same species.

_____ 5. Interspecific competition often leads to extinction, or it may lead to greater specialization.

_____ 6. A keystone species is one that plays an especially important role in its population.

_____ 7. Rock that hardens from lava is an example of primary succession.

_____ 8. Mutualism is a symbiotic relationship in which both species benefit.

_____ 9. The first species to colonize a disturbed area such as this are called primary species.

_____ 10. If a parasite kills its host, the parasite may also die.

_____ 11. Intraspecific competition leads to the evolution of better adaptations within a species.

_____ 12. Secondary succession may occur after a forest fire.

_____ 13. A population consists of all the communities of all the species in the same area.

_____ 14. There are three major types of community interactions: predation, competition, and selection.

_____ 15. Lichens that can live on bare rock may be pioneer species after a flood.

Name___________________ Class______________ Date________

Read these passages from the text and answer the questions that follow.

Symbiotic Relationships

Symbiosis is a close relationship between two species in which at least one species benefits. For the other species, the relationship may be positive, negative, or neutral. There are three basic types of symbiosis: mutualism, commensalism, and parasitism.

Mutualism

Mutualism is a symbiotic relationship in which both species benefit. An example of mutualism involves goby fish and shrimp (see figure below). The nearly blind shrimp and the fish spend most of their time together. The shrimp maintains a burrow in the sand in which both the fish and shrimp live. When a predator comes near, the fish touches the shrimp with its tail as a warning. Then, both fish and shrimp retreat to the burrow until the predator is gone. From their relationship, the shrimp gets a warning of approaching danger. The fish gets a safe retreat and a place to lay its eggs.

The multicolored shrimp in the front and the green goby fish behind it have a mutualistic relationship. (Image courtesy of Haplochromis and under the Creative Commons license CC-BY-SA 3.0.)

Commensalism

Commensalism is a symbiotic relationship in which one species benefits while the other species is not affected. One species typically uses the other for a purpose other than food. For example, mites attach themselves to larger flying insects to get a “free ride.” Hermit crabs use the shells of dead snails for homes.

Parasitism

Parasitism is a symbiotic relationship in which one species (the parasite) benefits, while the other species (the host) is harmed. Many species of animals are parasites, at least during some stage of their life. Most species are also hosts to one or more parasites. Some parasites live on the surface of their host. Others live inside their host. They may enter the host through a break in the skin or in food or water. For example, roundworms are parasites of mammals, including humans, cats, and dogs. The worms produce huge numbers of eggs, which are passed in the host’s feces to the environment. Other individuals may be infected by swallowing the eggs in contaminated food or water.

Some parasites kill their host, but most do not. It’s easy to see why. If a parasite kills its host, the parasite is also likely to die. Instead, parasites usually cause relatively minor damage to their host.

Questions

1. What is symbiosis?

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2. What is mutualism? Give an example.

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3. What is commensalism? Give an example.

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4. What is parasitism? Give an example.

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5. Why don't most parasites kill their host?

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Lesson 12.1: Multiple Choice

Name___________________ Class______________ Date________

Circle the letter of the correct choice.

1. Which of the following would NOT be a community?
1. All the plants, insects, and soil in your back yard.
2. All the many varieties of dogs in your neighborhood.
3. All the fish in an aquarium.
4. none of the above
2. Community interactions include
1. predation.
2. competition.
3. symbiosis.
4. all of the above.
3. Which is an example of a predator-prey relationship?
1. The relationship between a duck and a pond of water.
2. The relationship between a lion and a zebra.
3. The relationship between a bee and a flower.
4. The relationship between a hen and a rooster.
4. The main difference among the types of symbiotic relationships is
1. how many species either benefit or are harmed.
2. how many species are eaten.
3. how many species are protected.
4. all of the above.
5. An example of interspecific competition is
1. two male birds competing for the same female.
2. two male lions competing to lead the same pride.
3. two species of big cats competing for the same antelope.
4. all of the above.
6. Which of the following is a parasite?
1. the goby fish
2. the hermit crab
3. the shrimp
4. the roundworm
7. Which could possibly be a pioneer species during primary succession?
1. the first grass on new soil
2. the first lichen on new rock
3. the first layer of grass in a new park
4. the first trees to grow in a new forest
8. Camouflage is
1. an adaptation that evolved through natural selection.
2. a necessary trait for commensalism.
3. part of a well-adapted pioneer species traits.
4. all of the above.

Lesson 12.1: Vocabulary I

Name___________________ Class______________ Date________

Match the vocabulary word with the proper definition.

Definitions

_____ 1. a species that plays an especially important role in its community

_____ 2. a symbiotic relationship in which both species benefit

_____ 3. a final stable stage

_____ 4. occurs in an area that has never before been colonized

_____ 5. the species that consumes members of another species

_____ 6. a symbiotic relationship in which one species benefits while the other species is not affected

_____ 7. the species that is consumed

_____ 8. the first species to colonize an area that has never before been colonized

_____ 9. the change in the numbers and types of species that live in a community over time

_____ 10. species that benefits in a symbiotic relationship in which another species is harmed

_____ 11. occurs in a formerly inhabited area that was disturbed

_____ 12. occurs between members of the same species

_____ 13. species that is harmed in a symbiotic relationship in which another species benefits

_____ 14. occurs between members of different species

Terms

a. climax community

b. commensalism

c. ecological succession

d. host

e. interspecific competition

f. intraspecific competition

g. keystone species

h. mutualism

i. parasite

j. pioneer species

k. predator

l. prey

m. primary succession

n. secondary succession

Lesson 12.1: Vocabulary II

Name___________________ Class______________ Date________

Fill in the blank with the appropriate term.

1. A glacier retreating is an example of ____________ succession.

2. ____________ is a relationship in which one species benefits while the other species is harmed.

3. Lions feed on the South African Cape buffalo: the lions are the ____________, and the buffalo are the ____________.

4. Symbiosis is a close relationship between two species in which at least one species ____________.

5. Specialization occurs when competing species evolve different ____________.

6. ____________ is a relationship between organisms that strive for the same resources in the same place.

7. Pioneer species includes ____________ that can live on bare rock.

8. A keystone species is one that plays an especially important role in its ____________.

9. ____________ is an adaptation that in prey helps them hide from predators.

10. ____________ competition occurs between members of different species.

11. A community consists of all the populations of all the ____________ in the same area.

12. All ____________ have populations of interacting species.

Lesson 12.1: Critical Writing

Name___________________ Class______________ Date________

Thoroughly answer the question below. Use appropriate academic vocabulary and clear and complete sentences.

Compare and contrast mutualism, commensalism, and parasitism.

Feb 23, 2012

May 11, 2015