Year 8 Science · Unit 1 · Lesson 19

Interpreting Evidence About Living Systems

Foundation Worksheet

Name

Date

Class

Learning Goals

Identify the three parts of a CER explanation: Claim, Evidence, Reasoning
Match each CER term to a definition and a biology example
Sort statements from an experiment into the correct CER category

Warm Up

Match each term to its definition

Draw a line connecting each term on the left to its correct definition on the right. Or write the matching letter next to each term.

Term	Your answer	Definition / Example
Claim		A. The biological mechanism that explains why the data pattern makes sense, it links evidence back to the scientific idea.
Evidence		B. A statement that directly answers the question, it says what the data shows but does not just copy numbers.
Reasoning		C. Specific values, observations, or measurements taken from data, a diagram, or a case study.
Interpret		D. "Plants grown in full sunlight had an average height of 24 cm after two weeks, compared with 11 cm in low light."
Pattern		E. Working out what a set of results means, rather than just repeating the numbers.
Case study		F. A trend or relationship found in data, for example, breathing rate increases as exercise intensity increases.

Your Turn

Sort it!

A student investigated how the amount of light affects plant growth. The sentences below are from their report. Write each sentence into the correct box: Claim, Evidence, or Reasoning.

Plants in full sunlight grew taller than plants in shade. The average height of full-sun plants was 24 cm; shade plants were 11 cm. Light is an important input for plant survival and growth. Light intensity affects the rate of plant growth. After 14 days, the full-sun group was 2.2× taller on average. Plants with more light access can grow more effectively because light is a key input they need. All plants were watered equally, 50 mL per day. Without enough light input, leaves cannot support normal plant growth and function. Greater light availability supports more rapid plant growth.

Claim

Evidence

Reasoning

Show What You Know

1. A student writes: "The breathing rate went from 14 to 24 breaths per minute after exercise." Explain why this is evidence but not yet a claim.

Recall 2 marks

2. Write a one-sentence Reasoning statement for this claim: "Breathing rate increases after exercise." Your reasoning should explain why the evidence makes sense, link the pattern back to the living system idea from the lesson.

Recall 2 marks

Wrap Up

In one sentence, what is the main difference between evidence and reasoning in a scientific explanation?