• 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. Diego counts 20 pulse beats in 15 seconds. What is the pulse rate in beats per minute? → 80Prompt: How many lots of 15 seconds are there in one minute?
2. What do arteries do? (carry blood away from the heart / digest food / carry blood back to the heart / make urine) → carry blood away from the heartPrompt: "A" for arteries, "A" for away.
3. Blood and circulation: which statement is NOT true? (Capillaries are tiny blood vessels where substances pass to and from cells. / Arteries carry blood to the heart. / White blood cells help fight infection. / Blood is always red; it is bright red with oxygen and darker red without.) → 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 malaria? (virus / bacterium / fungus / protist) → protistPrompt: Colds and flu cannot be treated with antibiotics.
2. What do antibodies do? (attach to specific antigens on pathogens, helping destroy them / clot the blood / digest food / carry oxygen) → attach to specific antigens on pathogens, helping destroy themPrompt: Each antibody fits one antigen, like a lock and key.

• 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? (Some bacteria have become resistant to antibiotics. / You can catch heart disease from someone else. / Mosquitoes spread malaria. / Skin is a barrier that stops many pathogens entering.) → You can catch heart disease from someone else.Prompt: Think about what each treatment really does.
2. Why should a doctor not give antibiotics for a cold? (Colds are not diseases. / Colds are caused by viruses, and antibiotics do not kill viruses. / Antibiotics make colds worse. / Antibiotics only work on fungi.) → Colds are caused by viruses, and antibiotics do not kill viruses.Prompt: What kind of pathogen causes a cold?

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