Scientific Inquiry & Diversity of Life — Extension · Life Science & Scientific Inquiry, Grade 7
Five focused units, a three-session investigation, chapter review, and chapter quiz.
Compare paper water absorption
Investigate
How can a fair repeated comparison test water absorption?
Materials
- Supplied trial records, paper, and a notebook
- Optional equal-area paper samples, clean room-temperature water, and a suitable balance
Before you begin
Use only clean water and an adult-approved basic setup. Keep spills away from electrical equipment. Supplied data complete the core task; no equipment purchase is needed.
Plan a fair test
Change paper type; measure water mass absorbed. Keep sample area, water contact, draining interval, and weighing method comparable.
Method
- Write the question, prediction, changed factor, measured outcome, and controlled conditions.
- If using the optional setup, compare dry and wet masses after the same water-contact and draining procedure; otherwise analyze the supplied records.
- Keep three trial readings per type rather than choosing a preferred result.
- Calculate mean absorption and numerical range. Draw a labeled bar graph with a zero baseline.
- Explain the measured pattern, identify a limitation, and propose a better next comparison.
Illustrative course data — use for analysis without equipment
Illustrative records: these are invented teaching data, not published measurements or the learner’s own observations. Actual measurements may differ; record them separately if you perform an optional suitable activity.
| Trial | A absorbed (g) | B absorbed (g) |
|---|---|---|
| 1 | 10 | 7 |
| 2 | 12 | 8 |
| 3 | 11 | 9 |
Analyze and explain
- How do means and ranges compare?
- Does the record show every brand or other material property?
- Which method detail could change the results?
What a strong explanation includes
- Explain the relevant biological process accurately.
- Use the supplied evidence and show calculation steps with units where needed.
- Connect a labeled model or mechanism with the claim.
- State an assumption, evidence limitation, or useful next observation.
Parent / teacher guide: discuss after the investigation
A averages 11 g and B 8 g, a 3 g difference. Both numerical ranges are 2 g. Under the stipulated matched conditions, A absorbs more in this invented record. It does not show that A is best for every task or establish all brands. Contact, draining, area, and repeated independent samples matter. A labeled graph and a controlled next comparison strengthen the explanation.
Compare this model with the learner’s actual evidence. Different measurements can support a different conclusion; check the reasoning and limitations, not matching wording.
Extend the chapter investigation by evaluating its evidence and proposing a better test.
Problem 1
Answer and explanation
A averages 11 g and B 8 g, a 3 g difference. Both numerical ranges are 2 g. Under the stipulated matched conditions, A absorbs more in this invented record. It does not show that A is best for every task or establish all brands. Contact, draining, area, and repeated independent samples matter. A labeled graph and a controlled next comparison strengthen the explanation.
Problem 2
Answer and explanation
A averages 11 g and B 8 g, a 3 g difference. Both numerical ranges are 2 g. Under the stipulated matched conditions, A absorbs more in this invented record. It does not show that A is best for every task or establish all brands. Contact, draining, area, and repeated independent samples matter. A labeled graph and a controlled next comparison strengthen the explanation.
Problem 3
Answer and explanation
A averages 11 g and B 8 g, a 3 g difference. Both numerical ranges are 2 g. Under the stipulated matched conditions, A absorbs more in this invented record. It does not show that A is best for every task or establish all brands. Contact, draining, area, and repeated independent samples matter. A labeled graph and a controlled next comparison strengthen the explanation.