Posted in P6 SBI3U Biology

6 SBI3U Onion Cells Homework

  • Do a proper scientific drawing of some onion cells under the microscope.
  • Find the length and width of your onion cell for both your photo and your scientific drawing.
  • By how many percent was your drawing length too big or too small compared to the photo? (you’ll have to figure out how to find this percent error!)
  • Although onion cells only have 8 chromosomes, they have more DNA than we do!

Find all the errors in my drawing above. 🤔

Posted in P6 SBI3U Biology

6 SBI3U Rules for Scientific Drawing

The point of scientific drawing is generating a 2D model of what you are observing under the microscope. It is a visual observation of your data. Therefore drawing from memory is not as accurate nor precise as drawing bit by bit from the image under the scope or from a photo you took looking through the ocular lens.  You are to draw what you actually see, not what you think you remember.

  1. Draw the circle which represents the field of view in the upper left part of your page. Your page must be an unlined sheet of paper.
  2. Only use pencil for everything.
  3. Label only structures you can confidently identify.
  4. Put the title of the specimen centered and underlined above the FOV circle.
  5. Put the magnification in brackets in the bottom-right just outside of the field of view.
  6. Labels must be vertically aligned to the right of the drawing.
  7. Label lines are to be totally horizontal but in some cases a vertical drop-down or extend-up line may be used. These are to be avoided where possible.
  8. Borders between structures are the most important and are to be drawn with clean, solid lines.
  9. Stippling is to be used when shading in areas that are darker (just tap it in!). No shading or cross-hatching is allowed.