Science lesson plan · 7th grade (Year 8 in England) · 45 minutes
Breathing, gas exchange and respiration
Human body and health
CCSS NGSS.MS-LS1-7CCSS NGSS.HS-LS1-7England: KS3 Biology: Gas exchange systemsEngland: KS3 Biology: Cellular respirationEngland: KS4 Combined Science: Cell biology
Objective and success criteria
Students will: Breathing, gas exchange and respiration.
- I can answer questions on today's skill on my own, without help.
- I can explain each step and say why it works.
- I can check my answer and spot a mistake.
Before and after
Needs first: Heart, blood and circulation
Leads to: Respiration without oxygen: muscles and yeast
Materials: Stopwatches, Body diagrams, Mini whiteboards, A diagram or short video clip of the idea, Printed student sheet (below).
Warm-up · 5 min
- Quick retrieval from earlier learning (Heart, blood and circulation). Students answer on mini whiteboards.
- Show answers together and note who needs support in the main task.
- Hiro counts 13 pulse beats in 15 seconds. What is the pulse rate in beats per minute? → 52Prompt: How many lots of 15 seconds are there in one minute?
- How many chambers does the human heart have? (1 / 6 / 4 / 2) → 4Prompt: Two atria and two ventricles.
- Blood and circulation: which statement is NOT true? (The heart is on the far left side of the chest. / Blood is always red; it is bright red with oxygen and darker red without. / White blood cells help fight infection. / Red blood cells carry oxygen.) → The heart is on the far left side of the chest.Prompt: One of these is a famous myth.
Hook · 5 min
- Ask everyone to find their pulse, then jump for 30 seconds and find it again.
- Share the objective: Breathing, gas exchange and respiration. Read the success criteria together.
I do: model it · 10 min
- Work through the example out loud, saying why you do each step, not just what you do.
- Example: Where does gas exchange happen in the lungs?
- Step 1: Oxygen diffuses from the alveoli into the blood, and carbon dioxide diffuses out.
- Step 2: So the answer is: in the alveoli (air sacs)
- Answer: in the alveoli (air sacs)
- Pause after each step and ask a student to say what comes next.
We do: guided practice · 10 min
- Do these together. Students try each step on whiteboards before you reveal it.
- Use the hints as prompts rather than giving the answer.
- Yeast respiring without oxygen produces… (lactic acid only / water only / oxygen and glucose / ethanol (alcohol) and carbon dioxide) → ethanol (alcohol) and carbon dioxidePrompt: This is used to make bread rise.
- Respiration: which statement is NOT true? (Plants respire as well as photosynthesise. / We breathe out only carbon dioxide. / Mitochondria are where aerobic respiration happens. / Aerobic respiration releases more energy than anaerobic respiration.) → We breathe out only carbon dioxide.Prompt: Respiration and breathing are different things.
You do: independent practice · 10 min
- Students work on the student sheet. Circulate and check the first two answers of every student early.
- Students who finish: write a question of their own for a partner, with the answer.
The 6 questions are on the student sheet below, with answers in the key.
Exit ticket · 5 min
- Two questions on their own. Sort answers into got it / nearly / not yet to plan the next lesson.
- During hard exercise, muscles may respire without enough oxygen. What do they make? (alcohol and carbon dioxide / starch / oxygen / lactic acid) → lactic acidPrompt: This is anaerobic respiration in animals.
- Respiration: which statement is NOT true? (We breathe out only carbon dioxide. / Aerobic respiration releases more energy than anaerobic respiration. / Respiration happens in every living cell. / Plants respire as well as photosynthesise.) → We breathe out only carbon dioxide.Prompt: Respiration and breathing are different things.
Watch out for
- Everyday meanings of words getting in the way of the science meaning: define key words explicitly.
- Remembering facts without the reason: ask "why?" and "what is the evidence?"
Support and stretch
Support
- Review first: Heart, blood and circulation.
- Use concrete materials: stopwatches.
- Give the first step of each question, or a partly worked example to finish.
- Pair with a confident partner for the guided practice.
Stretch
- Move on to: Respiration without oxygen: muscles and yeast.
- Explain a common mistake in writing and how to fix it.
- Write a word problem that uses today's skill, then solve a partner's.
Homework and more practice
Free online practice with hints and printable worksheets for this skill: eurekami.com/science/grade-7.
Free lesson plan from eurekami.com/lesson-plan-builder