KS3 Biology › Breathing and respiration

Breathing, Respiration and Gas Exchange

These three get used as if they mean the same thing, and they don't. Breathing moves air. Gas exchange happens in your lungs. Respiration happens inside every cell you have. Keep them separate and the whole topic falls into place — including why rescue breaths work at all.

KS3 Biology · Year 7–9 · Free worksheet with answers

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What you'll be able to do after this lesson

These are the points the worksheet questions are built around.

Describe what air is made of and explain why nitrogen plays no part in breathing
Define breathing and describe how air moves in and out of the lungs
Explain what gas exchange is and where in the body it happens
Explain what cellular respiration is and why it happens in mitochondria
Compare breathing, gas exchange and respiration and say where each takes place
Explain how exhaled air differs from inhaled air, and why rescue breaths work

Revising for a test?

Every key term, learning objective and quiz question on one clean, printable page.

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Quick quiz — from the video

The 3 questions from the video, if you'd like to check you caught them.

1. Which gas makes up most of the air you breathe in?

2. Which of these does NOT happen during gas exchange?

3. A candle burns out faster in exhaled air. Why?

🎮 Want more practice? Try the 30-second Quiz Challenge →

Free worksheet — 3 questions, 13 marks

One page with a full answer key. Enough to check the lesson landed, and to see how the questions are written before you buy anything.

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Take it further

Every resource comes with a full answer key and marking guidance. Instant download, yours to keep, print as many copies as your class needs.

Full worksheet

£3

100 marks
Three sections of increasing difficulty
Word banks on every fill-in-the-blank
Complete answer key

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Extension pack

£3

Vocabulary matching
Challenge quiz
Case study
Teach It Back, with rubric

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Complete lesson pack

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The full worksheet and the extension pack together
Both answer keys included
Everything for the lesson and the follow-up — no preparation required
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Using this with a class

You're welcome to embed the video and link these resources in Google Classroom, Stile, Canvas, Compass or any other school platform. No need to ask.

Everything here is written to the KS3 curriculum for students aged 11–14. Print freely for the classes you teach.

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