Systems : Systems Lesson 2
Objectives : Objectives Describe a system as a group of related parts with specific roles that work together to achieve an observed result.
Explain the order in a system.
Distinguish between system inputs, system processes, system outputs, and feedback.
Distinguish between open loop and closed systems.
Explain how components of natural and human-made systems play different roles in a working system.
State Standards : State Standards Pennsylvania State Science Standard:
3.1 – Unifying Themes
7.A – Explain the parts of a simple system and their relationship to each other.
Slide 4 : Systems
Systems : Systems A system is a group of parts that work together to do a job, perform a function, or produce a result.
Systems can be natural or human-made.
Slide 6 : Parts of a System
Parts of a System : Parts of a System All systems are made of parts that work together.
Smaller systems can be parts of larger systems.
Each part of a system has a specific function, or role in the system.
If one part of a system is missing or does not fulfill its role, the system may not produce the expected result.
Practice Question #1 : Practice Question #1 Suppose all of the decomposers in an ecosystem died.
A. Describe what would most likely happen to the producers.
B. Describe what would most likely happen to the primary and secondary consumers.
Parts of a System : Parts of a System Most systems have inputs, processes, and outputs.
An input is something that goes into the system.
A system process is something that happens within the system.
An output is something that comes out of a system.
Model of a System : Model of a System INPUT INPUT PROCESS PROCESS PROCESS PROCESS OUTPUT OUTPUT OUTPUT
Parts of a System : Parts of a System Many systems have feedback mechanisms to control how they work.
In a feedback mechanism, the effects of a change in a part or process in a system help control that part or process.
Feedback mechanisms help keep the parts of a system stable. INPUT OUTPUT PROCESS
Slide 12 : Organization in
Systems
Organization in Systems : Organization in Systems Most systems have some form of organization.
Some systems are organized into steps and the steps happen in a specific order.
Other systems are organized into levels.
Each level is larger or more complex than the previous level.
Organization in Systems : Organization in Systems Organism (person) Organ System (circulatory system) Organ (heart) Tissue (cardiac muscle tissue) Cell (muscle cell)
Practice Question #2 : Practice Question #2 Which of these gives the levels of organization in the universe from smallest to largest?
A. galaxy, solar system, planet, universe
B. galaxy, universe, solar system, planet
C. planet, galaxy, universe, solar system
D. planet, solar system, galaxy, universe
Slide 16 : Types of Systems
Types of Systems : Types of Systems Scientists often put systems into groups.
Usually the groups are either natural or human-made.
Another way to group systems is either closed-loop or open-loop.
In a closed-loop system, the output of the system goes back into the system as an input.
The cycles of nutrients on Earth are closed-loop systems.
Closed-loop System : Closed-loop System
Types of Systems : Types of Systems In an open-loop system, the outputs of the system do not become inputs to the system.
Materials can enter and leave the system.
A food chain is an example of an open-loop system. SUN GRASSHOPPER GRASS FROG
Practice Question #3 : Practice Question #3 Which of these is the best example of a part in a closed-loop system?
A. the ink in a ball-point pen
B. the cars on a large state highway
C. the information in a desktop computer
D. the electricity in a complete electrical circut
Key Vocabulary : Key Vocabulary System
Function
Input
Process
Output
Feedback Mechanism
Closed-loop system
Open-loop system