• 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.

1. Yuki counts 18 pulse beats in 30 seconds. What is the pulse rate in beats per minute? → 36Prompt: How many lots of 30 seconds are there in one minute?
2. Why does your heart beat faster when you run? (Your muscles need more oxygen and glucose. / Your heart gets scared. / Your blood gets heavier. / Your lungs stop working.) → Your muscles need more oxygen and glucose.Prompt: Working muscles respire faster.
3. Blood and circulation: which statement is NOT true? (Arteries carry blood to the heart. / Veins carry blood back to the heart. / White blood cells help fight infection. / Capillaries are tiny blood vessels where substances pass to and from cells.) → Arteries carry blood to the heart.Prompt: One of these is a famous myth.

• Ask everyone to find their pulse, then jump for 30 seconds and find it again.
• Share the objective: Pathogens, immunity and vaccines. Read the success criteria together.

• Work through the example out loud, saying why you do each step, not just what you do.
• Example: What type of pathogen causes malaria?
• Step 1: Protists are single-celled organisms; malaria is spread by mosquitoes.
• Step 2: So the answer is: protist
• Answer: protist
• Pause after each step and ask a student to say what comes next.

• Do these together. Students try each step on whiteboards before you reveal it.
• Use the hints as prompts rather than giving the answer.

1. What type of pathogen causes Salmonella food poisoning? (virus / bacterium / fungus / protist) → bacteriumPrompt: Colds and flu cannot be treated with antibiotics.
2. Why should a doctor not give antibiotics for a cold? (Antibiotics make colds worse. / Colds are not diseases. / Antibiotics only work on fungi. / Colds are caused by viruses, and antibiotics do not kill viruses.) → Colds are caused by viruses, and antibiotics do not kill viruses.Prompt: What kind of pathogen causes a cold?

• 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 8 questions are on the student sheet below, with answers in the key.

• Two questions on their own. Sort answers into got it / nearly / not yet to plan the next lesson.

1. Disease: which statement is NOT true? (All bacteria cause disease. / Antibiotics kill bacteria but not viruses. / Skin is a barrier that stops many pathogens entering. / Mosquitoes spread malaria.) → All bacteria cause disease.Prompt: Think about what each treatment really does.
2. How does a vaccine protect you? (It is an antibiotic. / It makes you ill so you learn to avoid germs. / It trains white blood cells to make antibodies quickly if the real pathogen arrives. / It kills every bacterium in your body.) → It trains white blood cells to make antibodies quickly if the real pathogen arrives.Prompt: Vaccines contain a harmless form of the pathogen or its antigens.

Free online practice with hints and printable worksheets for this skill: eurekami.com/science/grade-9.