• 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: an invasive species? (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 % → 1 30 % → 4 50 % → 7 70 % → 10 90 % → 13 Which conclusion do the data support? (The tree eats the daisies. / Daisies grow best in the shade. / The data prove that light is the only factor that matters. / More daisies grow where light intensity is higher.) → More daisies grow where light intensity is higher.Prompt: Look at how the number of daisies changes as light changes.
3. Lichens grow less well near busy roads. Which abiotic factor is the likely cause? (competition with trees / air pollution such as nitrogen dioxide / a new disease / the number of predators) → air pollution such as nitrogen dioxidePrompt: Lichens are used as indicators of air quality.

• 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: 15, 30, 60, 114, 186, 246, 285, 300, 297. Which value is closest to the carrying capacity? (114 / 150 / 300 / 600) → 300Prompt: 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 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. A deer population grew from 200 to 250 in one year. What was the percentage growth rate? → 25 %Prompt: Find the increase.
2. A population of yeast cells (thousands per cm³) was counted each day: 9, 18, 36, 68, 112, 148, 171, 180, 178. Which value is closest to the carrying capacity? (68 / 90 / 180 / 360) → 180Prompt: The carrying capacity is where the population levels off.

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