Year 8 Science · Unit 1 · Lesson 16
Apply Worksheet
Learning Goals
Match each part of an investigation to what it is
Write the matching letter in the middle column. Each letter is used once.
| Part | Letter | What it is |
|---|---|---|
| Testable question | A. An answer to the question, based on evidence from the data. | |
| Prediction | B. Safe, fair steps that say exactly what to do and measure. | |
| Method | C. A trend in the results, such as “rose, then fell”. | |
| Secondary data | D. A statement of what may happen, with a reason. | |
| Pattern | E. Results collected by someone else, such as a published table. | |
| Conclusion | F. A question that can be answered by measuring or observing. |
True or false? Fix the false ones
Circle T or F. If a statement is false, correct it on the line.
1. A good conclusion always agrees with the prediction.
Correct it:
2. Only experiments done in a laboratory count as scientific investigations.
Correct it:
3. Results that surprise you can still be useful, because they can lead to new questions.
Correct it:
4. In a fair test, only the thing being tested is changed, and everything else is kept the same.
Correct it:
Prediction or guess?
A useful prediction says what will happen and gives a reason linked to the living system. Write “prediction” or “guess” for each, and give a reason.
| Statement | Prediction or guess? Why? |
|---|---|
| “Something will probably happen to the plant.” | |
| “My breathing rate will rise after I run, because my muscles will need more oxygen.” | |
| “Seedlings watered with salty water will wilt sooner than seedlings given tap water, because their roots will take in less water.” | |
| “I reckon the result will be interesting.” |
1. Choose one of the guesses above. Rewrite it as a reasoned prediction about a plant or an animal.
Read the data
Scenario: a gum seedling on five days
Tran found this table in a published report. The researchers sealed the pot of a gum seedling in plastic so that no water could evaporate from the soil. They weighed it each evening and topped the water back up, to find how many grams the seedling gave off each day. One gram of water is one millilitre.
| Day | Highest temperature (°C) | Water lost (g) |
|---|---|---|
| Monday | 24 | 61 |
| Tuesday | 18 | 42 |
| Wednesday | 31 | 88 |
| Thursday | 35 | 97 |
| Friday | 22 | 55 |
Source: sample data, written for this worksheet as if it came from a report.
2. Is Table 1 primary or secondary data for Tran? Give a reason.
3. The days are not listed from coolest to hottest. Find the pattern between temperature and water lost. Then calculate how much more water the seedling lost on the hottest day than on the coolest day.
Answer g
4. Tran writes: “This proves that heat makes all plants lose more water.” Give two reasons why this conclusion goes further than the data, and rewrite it so that it matches the evidence.
5. Scientists at the Australian Museum study frogs across Australia using recordings of frog calls that members of the public send in through the FrogID app. Explain why this counts as a scientific investigation, even though it does not happen in a laboratory. Describe what the scientists would do at each step, from question to conclusion, and explain why their conclusion must come from the data even if it surprises them.
Match each part of an investigation to what it is
Testable question → F; Prediction → D; Method → B; Secondary data → E; Pattern → C; Conclusion → A.
True or false
1. False: a conclusion must come from the data, even if the result is different from the prediction. 2. False: field observations and studies using secondary data also count. 3. True. 4. True.
Prediction or guess?
“Something will probably happen”: guess (says nothing about what will happen and gives no reason). Breathing rate: prediction (says what will happen and why). Salty water: prediction (clear outcome, reason linked to the roots). “Interesting”: guess (no outcome that can be measured, no reason).
1. Model: “A plant kept in the dark will grow less than one kept in the light, because it needs light to make its food.” [2 marks: 1 measurable outcome, 1 reason linked to the living system]
Read the data
2. Secondary: Tran did not collect it; it came from a published report. [1 mark]
3. Pattern: the hotter the day, the more water the seedling lost (18 °C: 42 g up to 35 °C: 97 g). Hottest (Thursday) minus coolest (Tuesday): 97 − 42 = 55 g. [3 marks: 1 pattern, 1 correct days chosen, 1 answer]
4. Any two: only one seedling of one kind of plant; only five days; “proves” is too strong; other things (sunlight, wind, humidity) may also have changed from day to day. Rewrite: “In this study, the gum seedling lost more water on hotter days.” [3 marks: 1 per reason, 1 rewrite]
Show What You Know
5. Marking guide (points expected): 1 investigations include field observations and data from other people, not only lab experiments; 1 question, e.g. “Are some frog species heard less often than they used to be?”; 1 prediction with a reason; 1 data: call recordings with place and date, checked to identify the species; 1 pattern: changes in where or how often each species is recorded; 1 conclusion must come from these patterns, even if they surprise the scientists, because the data show what actually happened. [6 marks]
Common error to watch for: in Q3, subtracting the first and last rows (Monday and Friday) instead of finding the coolest and hottest days.