Back to the lesson plan builder
Lesson length30 min45 min60 min
Questions🔀 New questions

Print the plan for yourself; the student sheet prints on its own page after it.

Science lesson plan · 11th grade (Year 12 in England) · 60 minutes

Population growth and carrying capacity

Ecosystems and food chains

CCSS NGSS.HS-LS2-1CCSS NGSS.HS-LS2-2CCSS NGSS.SEP 5England: GCSE Combined Science: Ecology

Objective and success criteria

Students will: Population growth and carrying capacity.

  • I can answer questions on today's skill on my own, without help.
  • I can explain each step and say why it works.
  • I can check my answer and spot a mistake.

Before and after

Needs first: Living and non-living factors in an ecosystem

Leads to: the next skill in this area.

Materials: Food web cards, Arrows to build chains, Mini whiteboards, A diagram or short video clip of the idea, Printed student sheet (below).

Warm-up · 6 min

  • 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: soil pH? (abiotic (non-living) / biotic (living)) → abiotic (non-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 % → 5 50 % → 9 70 % → 13 90 % → 17 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. / Light has no link with the number of daisies. / Daisies grow best in the shade.) → 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 / the number of predators / a new disease) → air pollution such as nitrogen dioxidePrompt: Lichens are used as indicators of air quality.

Hook · 6 min

  • 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.

I do: model it · 12 min

  • 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.

We do: guided practice · 12 min

  • 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 1000 to 1100 in one year. What was the percentage growth rate? → 10 %Prompt: Find the increase.

You do: independent practice · 17 min

  • 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.

Exit ticket · 7 min

  • Two questions on their own. Sort answers into got it / nearly / not yet to plan the next lesson.
  1. A population of yeast cells (thousands per cm³) was counted each day: 8, 15, 30, 57, 93, 123, 143, 150, 149. Which value is closest to the carrying capacity? (57 / 75 / 150 / 300) → 150Prompt: The carrying capacity is where the population levels off.
  2. A deer population grew from 800 to 1000 in one year. What was the percentage growth rate? → 25 %Prompt: Find the increase.

Watch out for

  • Everyday meanings of words getting in the way of the science meaning: define key words explicitly.
  • Remembering facts without the reason: ask "why?" and "what is the evidence?"

Support and stretch

Support

  • Review first: Living and non-living factors in an ecosystem.
  • Use concrete materials: food web cards.
  • Give the first step of each question, or a partly worked example to finish.
  • Pair with a confident partner for the guided practice.

Stretch

  • Explain a common mistake in writing and how to fix it.
  • Write a word problem that uses today's skill, then solve a partner's.

Homework and more practice

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

Free lesson plan from eurekami.com/lesson-plan-builder

eurekami

Population growth and carrying capacity

Name

Date

Score/ 8

  1. Question 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?

    • A. 114
    • B. 150
    • C. 300
    • D. 600

  2. Question 2

    Why does a population stop growing when it reaches carrying capacity?

    • A. Carrying capacity is always 100
    • B. Limiting factors such as food, space and disease balance births and deaths
    • C. The animals decide to stop breeding
    • D. The population runs out of DNA

  3. Question 3

    A deer population grew from 400 to 500 in one year. What was the percentage growth rate?

    Answer%

  4. Question 4

    A deer population grew from 400 to 420 in one year. What was the percentage growth rate?

    Answer%

  5. Question 5

    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?

    • A. 76
    • B. 100
    • C. 200
    • D. 400

  6. Question 6

    An invasive species arrives on an island with no predators. What is most likely at first?

    • A. native species grow faster
    • B. nothing changes
    • C. rapid population growth that may harm native species
    • D. the invasive species dies out at once

  7. Question 7

    A deer population grew from 200 to 240 in one year. What was the percentage growth rate?

    Answer%

  8. Question 8

    A population of yeast cells (thousands per cm³) was counted each day: 20, 40, 80, 152, 248, 328, 380, 400, 396. Which value is closest to the carrying capacity?

    • A. 152
    • B. 200
    • C. 400
    • D. 800

Free from eurekami.com

for the adult only

Answer key: Population growth and carrying capacity

  1. 1. C. 300

  2. 2. B. Limiting factors such as food, space and disease balance births and deaths

  3. 3. 25 %

  4. 4. 5 %

  5. 5. C. 200

  6. 6. C. rapid population growth that may harm native species

  7. 7. 20 %

  8. 8. C. 400