Year 8 Science · Unit 4 · Lesson 11
Apply Worksheet
Learning Goals
Find the flaw
A student's CER response about a plant growth investigation contains three errors — one in each part. For each row: (1) explain what is wrong, and (2) write an improved version. The investigation question was: "Does the amount of light a plant receives affect its height after two weeks?"
| CER part | Student's original (flawed) | What is wrong with it? | Your improved version |
|---|---|---|---|
| Claim | "The experiment worked well." | ||
| Evidence | "The results showed a trend." | ||
| Reasoning | "Because science." |
Hint for improved claim: plants in 8 hours light grew to 22 cm; plants in 2 hours light grew to 9 cm.
Plant growth data
Four fertilisers were tested on identical pea seedlings grown under the same conditions over 3 weeks. Average final heights: Fertiliser A = 24 cm, Fertiliser B = 18 cm, Fertiliser C = 31 cm, Fertiliser D = 12 cm. A control group (no fertiliser) reached an average height of 10 cm. All other conditions — light, water, soil type, temperature — were kept the same.
Write a full CER response to the question: "Which fertiliser produced the best plant growth?" Use the scaffolded boxes below.
Claim — Write one clear sentence that answers the investigation question.
Evidence — Quote at least two specific data values from the investigation to support your claim.
Reasoning — Explain in 1–2 sentences why your chosen fertiliser produced better growth. Use ideas about nutrients, photosynthesis, or plant biology.
1. A student writes: "The dissolving time decreased as temperature increased." Is this a claim, evidence, or reasoning? Explain your answer and improve it to make it a complete CER element of that type.
2. Why is reasoning the most challenging part of the CER framework? What happens to a scientific argument when reasoning is missing?
Wrap Up
In one sentence, what was the main idea of this lesson?