• Quick retrieval from earlier learning (Match cell parts to the jobs they do). Students answer on mini whiteboards.
• Show answers together and note who needs support in the main task.

1. Which part of a cell matches this description: a rigid layer of cellulose that strengthens the cell? (cell wall / ribosomes / mitochondria / cell membrane) → cell wallPrompt: Think about which part controls, which part makes energy available and which part lets things in and out.
2. What does the cell wall do? (a rigid layer of cellulose that strengthens the cell / a thin, flexible layer around the cytoplasm / where aerobic respiration releases energy from glucose / contain chlorophyll to absorb light) → a rigid layer of cellulose that strengthens the cellPrompt: Match the name to its job, not to where it is.
3. Cells in a carrot root are not green. Which part do they lack? (cell wall / nucleus / mitochondria / chloroplasts) → chloroplastsPrompt: Roots grow in the dark soil.

• Show a microscope image of cells and ask what students think they are looking at.
• Share the objective: Prokaryotic and eukaryotic cells. Read the success criteria together.

• Work through the example out loud, saying why you do each step, not just what you do.
• Example: Where is this found: a single loop of DNA not in a nucleus?
• Step 1: Prokaryotes (bacteria) have no nucleus: their DNA is a single loop, often with extra rings called plasmids.
• Step 2: So the answer is: prokaryotic cells only
• Answer: prokaryotic cells only
• 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. Where is this found: a nucleus? (prokaryotic cells only / eukaryotic cells only / both types of cell) → eukaryotic cells onlyPrompt: “Pro-karyote” means “before nucleus”.
2. A bacterial cell is about 2 µm long and a cheek cell is about 60 µm. How many times longer is the cheek cell? (3 times / 30 times / 300 times / 120 times) → 30 timesPrompt: Divide the larger size by the smaller one.

• 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.

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

1. Which organism is made of prokaryotic cells? (a mushroom / an amoeba / E. coli bacteria / yeast) → E. coli bacteriaPrompt: Which one has no nucleus?
2. Prokaryotes and eukaryotes: which statement is NOT true? (Eukaryotic cells keep their DNA inside a nucleus. / Some bacteria have a flagellum to move. / Both prokaryotic and eukaryotic cells have ribosomes. / Bacteria have mitochondria.) → Bacteria have mitochondria.Prompt: Do bacteria have mitochondria?

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