Using a light microscope, preparing a temporary slide, the syllabus drawing rules and calculating magnification.
5 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.
Drawing is worth 10 SBA marks — and up to 9 marks in a single Paper 2 question. Every mark is about following the rules.
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.
Eyepiece × objective (e.g. ×10 × ×40 = ×400).
Low power first; coarse then fine; only fine focus on high power.
Thin tissue, flat, in water/iodine; coverslip at an angle; blot.
Pencil, large, clean continuous lines, no shading, ruled horizontal labels on the right, annotations, title + view + magnification.
Drawing size ÷ actual size (same units).
Iodine for plant cells (nuclei, starch).
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.
| Rule | Why |
|---|---|
| Sharp HB pencil, no pen | Fine lines; mistakes can be erased |
| Large — at least half the space given | Details can be seen and labelled |
| Clean, continuous lines; no shading | Outlines must be clear and unambiguous |
| Correct proportions | The drawing must be an accurate record |
| Ruled label lines, no arrowheads, not crossing | Clear which structure each label names |
| Labels horizontal, in a neat column | Easy to read |
| Title: specimen, view, magnification | Says what was drawn and at what size |
Tick each rule before you hand in any drawing.
Magnification triangle: Image (drawing) on top, Actual × Magnification below — “I AM”: I = A × M.
Medical laboratory technologists in Caribbean hospitals use microscopes every day to identify blood cells and pathogens such as the malaria parasite — accurate observation and recording are core professional skills.
Draw a leaf from your yard following every rule on the checklist. Measure the real leaf and your drawing, and write the magnification in the title.
4 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]
A student draws one cell from onion epidermis viewed at ×400.
(a) List SIX rules the student must follow to score full marks for the drawing. [6]
(b) The student’s drawing of a bean seed is 75 mm long; the seed is 15 mm long. Calculate the magnification (show working). [2]
Everything in this lesson is based on these parts of the CXC syllabus and papers.