Biological Drawings and Diagrams
Drawings and diagrams are an essential part of communication in science, and especially biology. Remember it is not an artwork or sketch! But rather it is a clear representation of what you observe which can be used to interpret what you saw.
Some rules to follow
Drawings and diagrams must:
- Be drawn in a sharp pencil for clear, smooth lines.
- Be large so that all structures can be clearly seen (at least 10 lines of paper).
- Be drawn in the middle of the page.
- Be two dimensional (no shading)!
- Have a heading or caption.
- Specify the section in which the specimen was sliced, i.e. transverse section (T/S), cross section (C/S), or longitudinal section (L/S).
- State the source of the drawing or diagram, i.e. From a biological specimen, a micrograph or a slide.
- Indicate the magnification or scale of the drawing, either in the caption or in the corner of the drawing.
- Label lines should be drawn and they must:
- be parallel to the top of the page and drawn with a ruler.
- not cross each other or have an arrow at the end.
- clearly indicate the structure which is being named.
- be aligned neatly, one below the other and preferably on one side of the page, unless there are many labels in which both sides can be used.
Look at the diagram below. Think about what makes the drawings below good and bad. You might make a list of your observations.
Two-Dimensional (2-D) and Three-Dimensional (3-D) Diagrams
Objects in Biology can be drawn in three dimensions because they have depth.
Diagrams of apparatus are generally drawn in two-dimensions so that the shape of each item of apparatus is simplified and looks similar to a section through the apparatus.