• Quick retrieval from earlier learning (Natural selection and resistance). Students answer on mini whiteboards.
• Show answers together and note who needs support in the main task.

1. What is selective breeding? (animals choosing their own mates in the wild / humans choosing parents with useful characteristics to breed / feeding animals more food / cloning one plant) → humans choosing parents with useful characteristics to breedPrompt: Farmers have done this for thousands of years.
2. A population of 200 bacteria contains 5% that are resistant to an antibiotic. The antibiotic kills all the others. How many bacteria survive? → 10Prompt: Only the resistant ones survive.
3. Before the Industrial Revolution most peppered moths were pale. Soot darkened tree bark, and dark moths became common. Why? (Pale moths painted themselves dark / Birds prefer to eat dark moths / Dark moths were better camouflaged, so fewer were eaten by birds / Soot changed the moths' genes directly) → Dark moths were better camouflaged, so fewer were eaten by birdsPrompt: Which moths could birds see more easily on dark bark?

• Show a microscope image of cells and ask what students think they are looking at.
• Share the objective: Evidence for evolution and how new species form. Read the success criteria together.

• Work through the example out loud, saying why you do each step, not just what you do.
• Example: Approximate % difference between human DNA and other primates: chimpanzee 1.2 %, orangutan 3.1 %, rhesus macaque 7 %. Which primate shares the most recent common ancestor with humans?
• Step 1: The smallest difference is 1.2 %.
• Step 2: So the answer is: chimpanzee
• Answer: chimpanzee
• 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. Approximate % difference between human DNA and other primates: orangutan 3.1 %, chimpanzee 1.2 %, rhesus macaque 7 %. Which primate shares the most recent common ancestor with humans? (orangutan / rhesus macaque / chimpanzee) → chimpanzeePrompt: Fewer DNA differences means less time since the two lines split.
2. Why are fossils good evidence for evolution? (Every organism that ever lived became a fossil / Deeper (older) rock layers show simpler organisms that changed gradually over time / Fossils are all the same age / Fossils show that species never change) → Deeper (older) rock layers show simpler organisms that changed gradually over timePrompt: The fossil record is incomplete but shows patterns.

• 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. Approximate % difference between human DNA and other primates: rhesus macaque 7 %, orangutan 3.1 %, gorilla 1.6 %. Which primate shares the most recent common ancestor with humans? (orangutan / gorilla / rhesus macaque) → gorillaPrompt: Fewer DNA differences means less time since the two lines split.
2. Why are fossils good evidence for evolution? (Deeper (older) rock layers show simpler organisms that changed gradually over time / Fossils show that species never change / Every organism that ever lived became a fossil / Fossils are all the same age) → Deeper (older) rock layers show simpler organisms that changed gradually over timePrompt: The fossil record is incomplete but shows patterns.

Free online practice with hints and printable worksheets for this skill: eurekami.com/science/grade-10.