Drawing Cells: Skills (SL IB Biology)

Drawing the ultrastructure of cells

• To record the observations seen under the microscope (or from photomicrographs taken) a labelled biological drawing is often made
• Biological drawings are line pictures that show specific features that have been observed when the specimen was viewed
• There are a number of rules/conventions that are followed when making a biological drawing

Drawing conventions

• The drawing must have a title
• The magnification under which the observations shown by the drawing are made must be recorded where possible
  • A scale bar may be used
• A sharp HB pencil should be used (and a good eraser!)
• Drawings should be on plain white paper
• Lines should be clear, single lines (no sketching)
• No shading
• The drawing should take up as much of the space on the page as possible
• Well-defined structures should be drawn
• The drawing should be made with proper proportions
• Label lines should not cross or have arrowheads and should connect directly to the part of the drawing being labelled
• Label lines should be kept to one side of the drawing (in parallel to the top of the page) and drawn with a ruler
• Drawings of cells are typically made when visualising cells at a higher magnification power, whereas plan drawings are typically made of tissues viewed under lower magnifications (individual cells are never drawn in a plan diagram)
• You are also expected to include the functions of organelles and cells as part of the annotations made

Examples of biological drawings

Scanning electron micrograph and drawing of a prokaryotic cell

Transmission electron micrograph and drawing of a plant cell