OCR A Level Biology:复习笔记2.1.3 Drawing 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 which 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

Guidelines for microscope drawings

• The conventions are:
  • The drawing must have a title
  • The magnification under which the observations shown by the drawing are made must be recorded
  • 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 thick shading)
  • 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 visualizing 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)

An example of a tissue plan drawn from a low-power image of a transverse section of a root. There is no cell detail present.

An example of a cellular drawing taken from a high-power image of phloem tissue.