Year 8 Science · Unit 1 · Lesson 17

Interpreting Evidence About Living Systems

Foundation Worksheet

Name

Date

Class

Learning Goals

Define claim, evidence and reasoning, and say what tables and diagrams show.
Sort the parts of an explanation and build one with the structure → role → function → effect frame.
Interpret a table of results instead of copying it.

Warm Up

Fill the gap

Choose the correct word from the word bank. Two words will not be used.

suggests opinion diagram copying table guess

A of results shows values you can compare. A labelled shows structures and where they are. Interpreting evidence means explaining what it about the living system, not just it out.

Match each word to its meaning

Write the matching letter in the middle column. Each letter is used once.

Word	Letter	Meaning
Claim		A. A trend in data, such as “rises, then falls”.
Evidence		B. A statement that answers the question being asked.
Reasoning		C. A report on one real example, such as a damaged plant.
Pattern		D. The science idea that links the evidence to the claim.
Case study		E. Measurements or observations from data, diagrams or case studies.

Your Turn

Sort it: claim, evidence or reasoning?

Case study: brown patches on the school oval

Brown patches appeared on the school oval in late summer, even though it was watered every night. The groundskeeper lifted squares of turf from brown and green areas to find out: What caused the brown patches?

Write each sentence in the correct box. Each box gets exactly three sentences.

Roots under the brown patches were about 1 cm long; under green grass, about 8 cm. Roots take in water and minerals for the plant. Curl grubs caused the brown patches. The soil under the brown patches was damp. Shorter roots take in less water, so the leaves dry out and turn brown. The patches were not caused by dry soil. Each square of brown turf had about 15 curl grubs (beetle larvae); each square of green turf had 1 or none. A problem in one part of a plant can affect the whole plant. Watering the oval more will not fix the patches.

Claim

Evidence

Reasoning

Put the explanation in order

A cut rose is standing in a vase of water, but it droops. Number the sentences 1 to 4 to build the explanation. Then write which part of the frame each sentence is: structure, role, function or effect.

Order (1–4)	Sentence	Part of the frame
	Xylem carries water up the stem to the leaves and petals.
	So the rose droops, even though its stem is standing in water.
	Without that water, the cells in the petals and leaves cannot stay firm.
	An air bubble has blocked the xylem tubes at the cut end of the stem.

Go Deeper

Read the data

Investigation: holding your breath

Five seated students each held their breath for as long as was comfortable while a teacher timed them. They rested, jogged on the spot for one minute, then held their breath again straight away.

Table 1. How long each student held their breath (seconds)

Student	At rest	Straight after jogging
Ava	42	19
Ben	35	15
Chloe	50	24
Dev	38	16
Eli	45	21

Source: sample class results.

1. Which student held their breath the longest at rest, and for how long?

Recall 1 mark

2. Calculate the average time the five students held their breath straight after jogging.

Apply 2 marks

Answer seconds

Show What You Know

3. Answer the question “Does jogging change how long a person can hold their breath?” Write a claim, give evidence with numbers from Table 1, and give reasoning that explains the result using what cells need during exercise.

Analyse 4 marks

Answer Key (for teachers)

Fill the gap

table; diagram; suggests; copying. Not used: opinion, guess.

Match each word to its meaning

Claim → B; Evidence → E; Reasoning → D; Pattern → A; Case study → C.

Sort it: claim, evidence or reasoning?

Claim: curl grubs caused the patches; not caused by dry soil; more watering will not fix them. Evidence: root lengths (1 cm and 8 cm); grub counts (15 and 1 or none); damp soil. Reasoning: roots take in water and minerals; shorter roots mean less water reaches the leaves; a problem in one part affects the whole plant.

Put the explanation in order

Reading down the table as printed: 2, 4, 3, 1. Frame parts, reading down: role; effect; function; structure.

Read the data

1. Chloe, 50 seconds. [1 mark]

2. (19 + 15 + 24 + 16 + 21) ÷ 5 = 95 ÷ 5 = 19 seconds. [2 marks: 1 working, 1 answer]

Show What You Know

3. Marking guide: 1 claim; 1 evidence with a numerical comparison; 2 reasoning (1 muscle cells use more oxygen during exercise, 1 more carbon dioxide is made and must be removed, so the body needs a new breath sooner). Model: Jogging shortens breath-hold time: the average fell from 42 s to 19 s, and every student dropped. Exercising muscle cells use oxygen faster and make more carbon dioxide, so the body needs a new breath sooner. [4 marks]

Common error to watch for: sorting a claim as evidence because it sounds factual (“The patches were not caused by dry soil”). Evidence is something that was measured or observed; a claim answers the question; reasoning is a science idea that would be true for any plant.