KS3 · Biology
Animal cell structure and functions
You're an animal, so you're built from animal cells: tiny, busy places where four structures each do their own job at once. Let's open one up.
Biology · Cell structure
Explore
tap a part — what is its job?
One animal cell, four structures, and each has its own job. Start at the outside and work in. For each part, ask yourself: what job would go undone if this part weren’t there?
Tap a part of the cell, or use the buttons, to read its job.
Now go the other way: from job to part
Which structure does each of these? Pick a card, then pick the structure.
Still to sort
Nucleus (0)
The control centre
Cell membrane (0)
The layer around the outside
Cytoplasm (0)
The jelly that fills the cell
Where the line is: Respiration is a chemical reaction too, but it has its own address: the mitochondria. “Most of the cell’s reactions” points to the cytoplasm.
Mitochondria (0)
Where respiration happens
Where the line is: The mitochondria release energy; they don’t decide what the cell does. Directing the cell is the nucleus’s job.
You’ve seen each part and its job. Now you get the job — can you find the part?
WHAT YOU'VE LEARNED
A quick recap of today's lesson.
Four parts, four jobs — and three things an animal cell doesn’t have.
What you need to know
- Cells are the fundamental unit of living things — the basic unit an organism is built from. An animal is made of animal cells.
- An animal cell has four structures to know: the nucleus, the cell membrane, the cytoplasm and the mitochondria.
- An animal cell has no cell wall, no chloroplasts and no large permanent vacuole.
The big picture
An animal is made of animal cells. Each animal cell has four structures with their own jobs: the nucleus contains DNA and controls the cell’s activities, the cell membrane controls what moves in and out, the cytoplasm is where most chemical reactions happen, and the mitochondria are where aerobic respiration releases energy. An animal cell has no cell wall, no chloroplasts and no large permanent vacuole.
Key points
Worked example
Problem
A student writes: “The cell membrane is in charge of the cell, because it controls things.” What is wrong, and how would you fix it?
⚠ Watch out
Calling the outer layer of an animal cell a “cell wall”. Animal cells have no cell wall — their outer layer is the cell membrane.
Memory hook
Picture the cell as a tiny workshop. The nucleus is the manager’s office: it keeps the DNA and runs things. The membrane is the guard on the door. The cytoplasm is the busy workshop floor where most of the work happens. The mitochondria release the energy that keeps everything going.
Check yourself
Cover the lesson. Can you name the four structures in an animal cell and give each one’s job in a single sentence? Then name the three structures an animal cell does NOT have.
Flashcards
(9)What is the fundamental unit of living things?
Name the four structures in an animal cell.
What does the nucleus do?
What does the cell membrane do?
What is cytoplasm, and what happens in it?
What happens in the mitochondria?
Name three structures an animal cell does NOT have.
What forms the outside edge of an animal cell?
Mitochondrion or mitochondria?
Tap any card to flip it, or use Study as deck to go through them one at a time. In the full lesson these run as a spaced-repetition deck — you rate each card Hard, Good or Easy and the tricky ones keep coming back until they stick.
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How this lesson was checked. This KS3 Biologylesson was published through Lightbulb Learning's human-designed editorial process — the educational standards, accuracy rules and publication checks it must pass were authored and approved by Philip Halpin. It passed subject-specific assessment, automated educational checks and technical publication verification before going live (publication checks completed 1 October 2026). Published pages are monitored, human spot-checking is ongoing across the lesson library, and anything found wrong is corrected or withdrawn. How our lessons are made and checked. Spotted a mistake? Email hello@lightbulblearning.co and we'll review it.