An organ system is a group of organs that work together to do a job the whole organism needs. In an animal, the circulatory system (heart, blood vessels, blood) delivers oxygen and nutrients; in a plant, the vascular system (xylem and phloem in roots, stems and leaves) carries water and sugars. If one organ fails, the system fails.
Your heart can't keep you alive on its own, and neither can your lungs. Why do organs only make sense as a team?
A short lesson with no simulation. You have met cells, tissues and organs. Now organs join up.
Engage: Commit to a prediction before you test anything. A wrong guess is fine: it shows you what to look for.
Explain: Use the particle model to explain what you saw.
Elaborate: Use the same idea in a new context.
Evaluate: Look back at your first ideas and what changed.
WidthMore contexts, same idea.
Make your prediction first. Help opens once you've locked it in.
EngageCommit to a prediction before you test anything. A wrong guess is fine: it shows you what to look for.
Engage: one organ goes wrong
ExplainUse the particle model to explain what you saw.
Explain: systems at work
In your book: draw a simple circulatory system and a plant's vascular system side by side. Label three organs in each and write one sentence on how they work together.
Match each part of the circulatory system to its job.
Heart
Arteries
Veins
Capillaries
Blood
Match each part of a plant's vascular system to its job.
Roots
Xylem
Phloem
Leaves
Elaborate TypicalUse the same idea in a new context.
Elaborate: the digestive system
Elaborate WiderUse the same idea in a new context.
Elaborate: a machine for an organ
EvaluateLook back at your first ideas and what changed.
Evaluate: look back
Write one sentence: "At first I thought… Now I think… because…"
Revision summary
An organ system is a group of organs working together to do a job the whole organism needs.
If any organ in a system fails, the system can't do its job.
Both systems solve the same problem: moving materials to every cell.
For teachers
Students name the organs of one animal system and one plant system, explain how they coordinate to do a survival job, and compare the two as solutions to a shared problem (AC9S8U02, node 4). About 15 minutes.
I can name organs of an animal and a plant system and say what each does.
I can say how the organs work as a system.
I can compare the two systems.
Before class
A short questions-led lesson with no simulation, following Tissues and organs. Set the width with ?width=minimum, typical (default) or wider. It is the key node of the unit (★) and rewards diagrams and models more than screens: a hand pump and tubing model of the circulatory system works well.
Board notes: none. Systems are simplified: the circulatory system has a double loop (heart to lungs and back, heart to body and back) that the Year 8 descriptor doesn't require.
Running the lesson
Engage: tally the predictions. Ask the 'nothing' group what the leg needs from the blood.
Explain: the two matches and the shared problem are the success criteria.
In your own words: the two labelled diagrams.
The hard part (on purpose)
Seeing the system, not a list of parts. When a student lists organs, ask them what job would stop if one were removed.
When students get stuck
A student says the heart makes blood. Ask: What does the heart do to blood that is already there? Fix: It pumps it. Blood is made in the bone marrow.
A student says plants have no system because they have no heart. Ask: How does water get from the root to the leaf? Fix: Through xylem, which is a transport system with no pump.
Stretch and support
Stretch: Why do large animals and tall trees both need transport systems, when a single-celled organism doesn't? (Diffusion works over tiny distances only.)
Support: Give a diagram of each system with the organs unlabelled and a word bank, and ask students to add one arrow for the direction of flow.
Where it leads
Next: Year 9 coordination and signals.
In class: model circulatory system with a hand pump and tubing; celery in coloured water to show xylem; take a pulse before and after exercise.
What each step is for
Engage: one organ goes wrong: Students treat each organ as independent. A system is defined by organs doing a job together, so failure of one affects the whole.
Explain: systems at work: Naming organs and their jobs, explaining how they coordinate, and comparing a plant and an animal system as answers to one problem meets the three success criteria.
Elaborate: the digestive system: A second animal system shows that the same analysis (organs, jobs, coordination) works for any system.
Elaborate: a machine for an organ: Artificial organs show the function an organ must perform, because engineers must copy it.
Now you can
Name organs of an animal and a plant system and say what each does.