2.1.3 Drawing Cells

• What is often made to record observations seen under a microscope?

  A labelled biological drawing
• What do biological drawings represent?

  Specific features observed in specimens
• What are the conventions for making a biological drawing?

  • Must have a title
  • Record magnification used
  • Use a sharp HB pencil
  • Draw on plain white paper
  • Use clear, single lines (no shading)
  • Take up as much space as possible
  • Draw well-defined structures
  • Maintain proper proportions
  • Label lines should not cross or have arrowheads
  • Keep label lines parallel to the top of the page and use a ruler
• What type of pencil should be used for biological drawings?

  A sharp HB pencil
• What should be avoided in biological drawings?

  No shading should be used
• How should label lines be drawn in a biological drawing?

  With a ruler and parallel to the top
• When are drawings of cells typically made?

  When visualizing cells at higher magnification
• What is a plan drawing typically made of?

  Tissues viewed under lower magnifications
• What is the difference between cellular drawings and plan drawings?

  • Cellular drawings:
  • Made from high-power images
  • Show detailed cell structures
  • Plan drawings:
  • Made from low-power images
  • Do not show cell detail
• What should you only ever draw in a biological drawing?

  What you see under the microscope
• What tool can help accurately reflect size and proportions in biological drawings?

  The eyepiece graticule
• What types of images should you be able to describe and interpret?

  Photomicrographs and electron micrographs
• What is an example of a tissue plan drawn from a low-power image?

  A transverse section of a root
• What is visible in a cellular drawing of phloem tissue?

  Cell wall and nuclei of companion cells
• What is not visible in a phloem sieve tube drawing?

  No cell contents visible