Examiners mark a biology diagram in seconds, and not for art. A biology teacher on clean lines and labels, the diagrams that come up again and again, and timed practice.
In a biology paper, the diagram is the part most students rush and most teachers wish they wouldn't. An examiner marks it in seconds, and they are not judging art. A plain, clean, well-labelled heart scores better than a beautiful one with label lines flying in every direction.
That is good news. Diagram marks are some of the most learnable marks in the paper, because the rules are few and they don't change from year to year.
What examiners look for
- Clean lines. One firm, continuous line for each edge, not a hairy sketch of many short strokes. No shading.
- Straight label lines. Drawn with a ruler, touching exactly the part they name, never crossing each other. Leave the arrowheads off: in biology an arrow means direction, such as blood flow or a nerve impulse.
- Neat labels. Outside the drawing, written level, lined up on one or both sides, and spelled exactly as your textbook spells them.
- A title. Say what it is and, for sections, which cut: “L.S. of human heart”, “T.S. of leaf”.
- Proportion and size. Parts roughly the right size compared with each other, and the whole drawing big enough to read, about a third to half of a page.
And draw what was asked. A question on the nephron does not want the whole kidney, and “draw a labelled diagram” means some of the marks sit in the labels.
The diagrams that come up again and again
Exactly which ones depends on your class and your board, but these typically appear year after year. Learn each one together with its usual mistake.
The human heart
Four chambers, the septum, the valves and the main vessels: aorta, pulmonary artery, pulmonary veins and venae cavae. The classic slip is swapping left and right. You are looking at the heart from the front, so its left side is on the right of your page. Draw the wall of the left ventricle thicker than the right one.
The neuron
A cell body with its nucleus, dendrites, a long axon, the myelin sheath with its gaps (nodes of Ranvier) and the axon endings. Students often draw the myelin as one unbroken tube. Add a single arrow beside the axon for the direction of the impulse: this is where an arrow belongs.
The nephron
Bowman's capsule around the glomerulus, the proximal convoluted tubule, the loop of Henle, the distal convoluted tubule and the collecting duct, with the afferent arteriole (coming in) drawn wider than the efferent arteriole (going out). The common slip is a loop that wanders across the page; keep it a neat U that dips down, with the parts in the right order.
Plant and animal cells
Often asked side by side. The plant cell has a cell wall outside the membrane, a large central vacuole, chloroplasts and a fairly regular shape. The animal cell has no wall and no chloroplasts, and only small vacuoles if any. Watch for round plant cells, chloroplasts in an animal cell, and a plant cell's nucleus drawn dead centre when the big vacuole usually pushes it to one side.
Others that typically appear include the digestive system, the lungs and alveoli, the eye, a flower in L.S., a leaf in T.S., stomata and the stages of mitosis. Go through your board's past papers for the last five years, list every diagram asked, and tick the ones that repeat. That list is your practice plan.
Practise with a timer
- Copy each diagram from your textbook once, slowly, saying each part's name as you label it.
- The next day, draw it from memory. Then put the book beside it and mark every difference in another colour.
- Draw it again against the clock. Start with ten minutes for a big diagram like the heart and work down to about six without losing neatness. A cell should take less.
- Do label drills: draw one clean outline, trace it a few times on blank paper, and practise only the labels.
- Come back to each diagram after a few days, then after a week. Testing yourself and spacing out practice are the two study habits that a major review of learning research rated most effective.
Swap diagrams with a friend and mark each other out of five: one mark each for lines, labels, title, proportion and spelling. You will spot in a friend's heart what you never see in your own.
Pencil and eraser habits
- Carry a sharp HB pencil (or a 0.5 mm mechanical pencil), a soft white eraser, a sharpener and a 15 cm ruler, all in a clear pouch.
- Draw faint lines first, then go over the final outline once, firmly, and rub out the guide lines.
- Don't press hard. A line pressed into the paper won't erase cleanly and leaves a groove.
- Hold the page flat with your other hand when you erase, and rub in one direction so it doesn't crumple or tear.
- Start in the middle of the space and leave room on both sides for labels.
- Place the diagram next to the answer it belongs to, and refer to it in your writing: “as shown in the diagram”.
- Skip colours unless the question asks for them. They take time that the next question needs.
Tonight, draw the heart from memory. Ten minutes, then check it against your book and fix it in another colour. Do it again on Saturday and see how much less there is to fix.
For more on testing yourself and spacing your practice, read our post on the new 40% pass mark and five study methods. And if you would like a biology teacher to check your diagrams every week, you can find the right teacher on Education360.
