Lessons · Teaching · cells, and what they are the unit of
Everything alive is made of cells, and plant cells have three extra parts
The cell is the smallest unit that is alive. Animal and plant cells both have a membrane, cytoplasm and a nucleus. Plant cells also have a cell wall for rigidity, a large vacuole for storage, and chloroplasts where light is captured.
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What it is for
The three extra parts are not trivia: they explain why a plant stands up without a skeleton, why a wilted plant recovers when watered, and why plants are green. A pupil who has the three parts can answer all three questions themselves.
How to think about it
Learn the shared parts first, then the three extras and what each one is FOR. Every time a plant behaves differently from an animal, ask which of the three explains it.
Worked example
Both have: membrane to control what enters, cytoplasm where reactions happen, nucleus holding instructionsThree parts, three jobs.
Plants add a cell wall, which is why a stem is rigid with no bonesRigidity from a box, not from a skeleton.
Plants add a vacuole, which is why a dry plant wilts and a watered one standsThe vacuole fills and pushes the wall out.
Plants add chloroplasts, which hold the green pigment and capture lightWhich is why plants are green and animals are not.
Your turn
Name the plant cell part that captures light.
Light is captured in the
Solve one, graded on the server
The trap
Saying a cell wall and a cell membrane are the same thing. Both animal and plant cells have a membrane; only plants add a wall outside it, and the wall is what makes a stem stiff.