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: temperature? (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: 90 % → 18 70 % → 14 50 % → 10 30 % → 6 10 % → 2 Which conclusion do the data support? (More daisies grow where light intensity is higher. / Light has no link with the number of daisies. / The tree eats the 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 / the number of predators / air pollution such as nitrogen dioxide / 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: 20, 40, 80, 152, 248, 328, 380, 400, 396. Which value is closest to the carrying capacity? (152 / 200 / 400 / 800) → 400Prompt: 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.

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: 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.
  2. A deer population grew from 1000 to 1100 in one year. What was the percentage growth rate? → 10 %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 deer population grew from 800 to 960 in one year. What was the percentage growth rate?

    Answer%

  2. Question 2

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

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

  3. Question 3

    A population of yeast cells (thousands per cm³) was counted each day: 12, 24, 48, 91, 149, 197, 228, 240, 238. Which value is closest to the carrying capacity?

    • A. 91
    • B. 120
    • C. 240
    • D. 480

  4. Question 4

    A deer population grew from 500 to 600 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: 9, 18, 36, 68, 112, 148, 171, 180, 178. Which value is closest to the carrying capacity?

    • A. 68
    • B. 90
    • C. 180
    • D. 360

  6. Question 6

    A deer population grew from 200 to 210 in one year. What was the percentage growth rate?

    Answer%

  7. Question 7

    Snowshoe hare and lynx populations rise and fall in cycles, with lynx peaks just after hare peaks. Why?

    • A. Lynx and hares compete for grass
    • B. More hares feed more lynx; then lynx eat so many hares that hare numbers fall
    • C. The two species never interact
    • D. Hares eat lynx

  8. Question 8

    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

Free from eurekami.com

for the adult only

Answer key: Population growth and carrying capacity

  1. 1. 20 %

  2. 2. B. rapid population growth that may harm native species

  3. 3. C. 240

  4. 4. 20 %

  5. 5. C. 180

  6. 6. 5 %

  7. 7. B. More hares feed more lynx; then lynx eat so many hares that hare numbers fall

  8. 8. C. 300