• Quick retrieval from earlier learning (Living and non-living factors in an ecosystem). Students answer on mini whiteboards.
• Show answers together and note who needs support in the main task.

1. Is this a biotic or an abiotic factor: a disease? (abiotic (non-living) / biotic (living)) → biotic (living)Prompt: Does it come from a living organism?
2. Students placed quadrats in a line leading out from under a tree. Light intensity (% of full sunlight) → number of daisies: 10 % → 2 30 % → 4 50 % → 6 70 % → 8 90 % → 10 Which conclusion do the data support? (The data prove that light is the only factor that matters. / More daisies grow where light intensity is higher. / Daisies grow best in the shade. / Light has no link with the number of daisies.) → More daisies grow where light intensity is higher.Prompt: Look at how the number of daisies changes as light changes.
3. Bee numbers fall in an area, and fewer apples form on the trees. Which factor has changed for the apple trees? (no factor has changed / an abiotic factor: day length / a biotic factor: fewer pollinators / an abiotic factor: soil pH) → a biotic factor: fewer pollinatorsPrompt: Bees are living things.

• Show a food web and ask what would happen if one animal disappeared.
• Share the objective: Population growth and carrying capacity. Read the success criteria together.

• Work through the example out loud, saying why you do each step, not just what you do.
• Example: A population of yeast cells (thousands per cm³) was counted each day: 15, 30, 60, 114, 186, 246, 285, 300, 297. Which value is closest to the carrying capacity?
• Step 1: The population stops growing at about 300.
• Step 2: So the answer is: 300
• Answer: 300
• 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. A population of yeast cells (thousands per cm³) was counted each day: 10, 20, 40, 76, 124, 164, 190, 200, 198. Which value is closest to the carrying capacity? (76 / 100 / 200 / 400) → 200Prompt: The carrying capacity is where the population levels off.
2. A deer population grew from 800 to 840 in one year. What was the percentage growth rate? → 5 %Prompt: Find the increase.

• 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. A deer population grew from 200 to 220 in one year. What was the percentage growth rate? → 10 %Prompt: Find the increase.
2. Why does a population stop growing when it reaches carrying capacity? (Carrying capacity is always 100 / The animals decide to stop breeding / The population runs out of DNA / Limiting factors such as food, space and disease balance births and deaths) → Limiting factors such as food, space and disease balance births and deathsPrompt: What becomes scarce as numbers grow?

Free online practice with hints and printable worksheets for this skill: eurekami.com/science/grade-11.