A STUDENT SHOULD KNOW THAT:

A. A SYSTEM IS A COLLECTION OF INTERACTING PARTS WORKING TOGETHER AS A WHOLE.

1. For example,
   1. Mechanical devices (bicycles, scissors, toy cars, clocks)
   2. Ocean
   3. Predator/prey, food chain/web
   4. A balanced aquarium
   5. Weather
   6. Human body/body system
   7. Ecosystems (freshwater, saltwater, ponds, desert, wetlands)
   8. Water cycle
   9. Plant systems (root, stems, leaves)
   10. Electric circuit
   11. Telephone
   12. Computers
   13. Camera
   14. Earth, moon, sun

B. SYSTEMS CAN DO THINGS THAT PARTS CANNOT DO SEPARATELY.

C. PARTS MAKE UP A WHOLE.

D. THERE EXIST MANY SYSTEMS IN THE LIVING AND NON-LIVING WORLD.

1. Dependencies among plants and animals can be complex. A particular plant or animal may be eaten by different types of animals, each of which in turn may be eaten by more than one type of animal. This complex network of two or more food chains is called a food web.
   1. The sun is the primary source of energy for all living things.
   2. The direction of the arrows in a food chain illustration shows the flow of energy. An example of a food chain is sun-- grass -- rabbit -- fox. The sun should be drawn first in an illustration of a food chain or food web.
2. In a system such as a bicycle, the foot moves the pedal; the pedal moves a chain; the chain moves the wheel; and the wheel moves the bicycle.

E. A SYSTEM MAY NOT WORK IF A COMPONENT IS MISSING.

A STUDENT SHOULD BE ABLE TO:

• Diagram a system.
• Organize components of a system into a concept map.
• Make inferences from observations and from collected data that a system is composed of interacting parts, e.g., weather and predator/prey relationships.
• Predict the outcome of removing a component from a system.