Science
Strand III
Use Scientific Knowledge from the Life Sciences in Real-World Contexts

 

Science/Strand III
Content Standard 5
All students will explain how parts of an ecosystem are related and how they interact; explain how energy is distributed to living things in an ecosystem; investigate and explain how communities of living things change over a period of time; describe how materials cycle through an ecosystem and get reused in the environment; and analyze how humans and the environment interact. (Ecosystems)

 

Science/Strand III/Content Standard 5
Middle School

 

Science/Strand III/Content Standard 5/Middle School
Benchmark 3

Predict the effects of changes in one population in a food web on other population.

Benchmark Clarification

Populations of plants, animals, and other organisms in an ecosystem coexist in a natural balance. As one population fluctuates, the other populations that depend upon it for survival will increase or decrease.

Populations may be affected:

  • When natural events, human activities, or introduction of non-native species change environments
  • During natural events such as disease, flood, and drought when this balance is altered, affecting the biodiversity within the community
  • When human activities such as the use of natural resources, pollution, construction, land development, and mining cause populations to change

Students will:

  • Predict the effects of changes on populations.

Key Concept / Real World Context / Instructional Example / Assessment Example / Resources

 

Science/Strand III/Content Standard 5/Middle School/Benchmark 3
Key Concept

  • natural balance
  • population
  • dependence
  • survival
  • community
  • biodiversity
  • introduction of non-native species

See (SCI.III.5.E.2).

 

Science/Strand III/Content Standard 5/Middle School/Benchmark 3
Real World Context
Plants and animals in an ecosystem dependent upon each other for survival in selected ecosystems

Comparison of animals and plants found in:

  • polluted versus non-polluted water
  • urban versus rural settings
  • rural versus forest settings
  • zebra mussels introduced into the Great Lakes
  • gypsy moths defoliating trees

 

Science/Strand III/Content Standard 5/Middle School/Benchmark 3
Instructional Example

Benchmark Question: How is energy distributed to living things in an ecosystem?

Focus Question: How does a change in one population affect the other organisms in a food web?

Students should envision a Michigan forest and describe the populations living in a natural balance. They should brainstorm a list of the different organisms that live there:

1. Plants: beech trees, maple trees, raspberry bushes, dogwood trees, moss, trillium

2. Animals: robins, white-tailed deer, squirrels, owls, mice, garter snakes, earthworms

3. Other: fungus, bacteria, lichens

Each student will construct a food chain:

1. Write the names of organisms on index cards

2. Punch a hole at the top of each card

3. Use yarn to show how organisms are connected in a food chain

4. Share his or her food chain with the group

In small groups, students will share their food chains to construct a food web and present their webs to the class. As a class, evaluate each group’s web to make sure they formed a food web and not just a food chain.

The teacher will present the following scenario to the class:

A camper is careless and leaves his or her site with a campfire burning. A spark ignites the dry grass due to drought conditions. This fire is stopped, but not before it wipes out the mouse population. Predict the changes that will occur in the other populations within the forest food web.

After reading the scenario, each student will remove the “mice” card from their webs. As a class, discuss which populations within the web may increase or decrease after the removal of the mice population from this ecosystem.

Constructing: (SCI.I.1.MS.1).

Reflecting: (SCI.II.1.MS.5).

 

Science/Strand III/Content Standard 5/Middle School/Benchmark 3
Assessment Example

Students will read a news article describing the deer population increase and its effects on other populations within its food web. They will write letters to the editor describing changes in a population. They will include both positive and negative effects on other populations in a food web and create a plan for solving the problems created by these population changes. The students will submit these letters for publication to a newspaper or magazine.

(Give students rubric before activity.)

Scoring Rubric

Criteria

Apprentice

Basic

Meets

Exceeds

Identification of population change

States one possible change in one population.

States clearly the possible changes that occur in two populations.

States clearly the possible changes that occur in three populations.

States clearly numerous changes that occur in four or more populations.

Description of population change

Describes one effect of the deer increase on other populations.

Describes two effects of the deer increase on other populations.

Describes three effects of the deer increase on other populations.

Describes detailed, numerous effects of the deer increase on other populations.

Correctness of mechanics

Shows limited use of proper writing mechanics.

Shows some use of proper writing mechanics.

Uses proper writing mechanics.

Uses proper writing mechanics in a highly expressive, creative manner.

 

Science/Strand III/Content Standard 5/Middle School/Benchmark 3
Resources

Webliography.
http://mtn.merit.edu/mcf/SCI.III.5.MS.3.html

“Catch Me If You Can.” Critters. AIMS.
http://wwws.aimsedu.org/aimscatalog/default.tpl

http://www.fi.edu/tfi/units/life/habitat/habact3.html

Merritt, Brett. Great Lakes Story. MSTA Journal, Spring 1998.

The Mysterious Chain. Flinn Scientific- Biolabs.(800/452-1261).

Nutrition/Populations. Bill Nye Video. Disney Educational. (800/295-5010).

PROJECT WILD.
http://www.projectwild.org/

The Tale of the Urban Coyote. (Leadership Resources.)

Williams, Paul. Bottle Biology. Kendall Hunt Publishing, 1993.