Measuring water loss by weighing and with a potometer, and investigating woodlice responses in a choice chamber — both in the specimen Paper 03/2.
4 narrated scenes. Press play, listen and read along — the points appear as they are explained. Use ‹ Prev / Next › or the scene bar to jump to any scene.
Both of these appear in the CXC specimen Paper 03/2. Know the set-ups and you can draw them from memory.
Narration uses your device’s built-in voice. No sound? Switch to “Captions only” — the captions advance on their own.
Copy these into your notebook in your own words — that is how they stick.
Shoot in a clear bag or pot sealed; weigh hourly; mass loss ≈ transpiration.
Measures water uptake; cut under water; airtight; bubble distance per time.
Light/dark, damp/dry zones; count at intervals; woodlice prefer dark & damp.
Darkness incomplete; conditions drift; small sample.
The kind of support a teacher gives after the lesson: worked examples to attempt first, a board illustration, key terms, common misconceptions and memory aids.
Try it in your notebook first, then reveal the solution one step at a time.
Try it in your notebook first, then reveal the solution one step at a time.
| Zone | Moisture | Light | How it is made |
|---|---|---|---|
| 1 | Damp | Dark | Wet filter paper underneath; covered with black paper |
| 2 | Damp | Light | Wet filter paper; uncovered |
| 3 | Dry | Dark | Drying agent (e.g. silica gel); covered |
| 4 | Dry | Light | Drying agent; uncovered |
Each quarter has a different combination of moisture and light.
Woodlice want D-D: Damp and Dark.
Gardeners in the Caribbean find woodlice and millipedes under pots, stones and leaf litter — exactly the damp, dark places the choice chamber predicts.
Look under five stones or flowerpots and five open patches of ground. Count the woodlice or millipedes in each and see if the results match the choice-chamber prediction.
3 quick games on this lesson. Earn XP and badges as you play — your best score for each game is saved. Games are for practice and do not change your exam readiness.
6 items modelled on real CSEC Paper 1 questions. Choose one answer for each, then check. Aim for 80% or better.
Write full answers, then reveal the mark scheme and tick the points you earned (8 marks in total). Your answers are saved on this device.
Question 1 [8 marks]
Transpiration and invertebrate behaviour.
(a) Describe (or draw) how a potted plant is set up and weighed to measure water loss. [3]
(b) Design a choice-chamber experiment on light and moisture for woodlice, stating ONE hypothesis and TWO precautions. [5]
Everything in this lesson is based on these parts of the CXC syllabus and papers.