Requirements in the biological drawings of TAS

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Requirements in the biological drawings of TAS
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• According to TAS, we can identify the following
  criteria for assessing biological drawings of
  students
• 1. Accuracy resemblance to the specimen
• correct shape and proportion
• 2. Smooth and clear lines
• 3. Correct labels or annotations
• 4. Title, plan of view and magnification
• 5. Large, overall neatness including the
• arrangement of labels and label lines

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Orientation

• Apart from naming the structures of your drawing
  correctly, you should describe how the section of
  the specimen is cut
• The followings are some common terms used to
  describe sections

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• 1. Transverse section (T.S.)
• at right angles to the long axis of a structure
  such as a stem also known as cross section
  (X.S.)
• 2. Longitudinal section (L.S.)
• along the long axis of a structure such as a
  stem
• 3. Vertical section (V.S.)
• at right angles to the surface of a structure
  such as the skin

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• 4. Whole mount (w.m.)
• 5. Teased, macerated, smear, etc.

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Title

• Always use a title
• You can use the words of the question to phrase
  your title
• Dont like this T.S. of a root
• Like this T.S. of specimen A

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• Write the title below the drawing and rather
  close to it
• Dont place the title at too great a distance
  from the drawing or in an ambiguous position such
  as mid-way between 2 drawings
• O.K.?

Structures of two guard cell
Structures of two guard cell
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Low power and high power drawings
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• Low power drawing
• Show the tissue layout / draw the whole or a
  representative part of the section to show all
  the different types of tissues which can be
  recognized
• Tissues should be in correct position and
  proportion

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• Do not attempt to draw individual cells in a low
  power drawing
• Low power drawing does not mean a drawing showing
  the features as seen under a low power
  magnification of the microscope, eg. 5x10 !

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• High power drawing
• Show the detailed structure of selected cell
  types identified in low power plan
• Adjacent cells should be drawn in their proper
  positional relationships and proportionate size
  to one another

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• For plant cell, the cell wall is usually
  comparatively thick, a double line should be used
  to represent the thickness
• If the wall is thin, single line can be used
• If cellular structures such as cytoplasm, nuclei,
  vacuoles and starch grains are visible under high
  power, they should also be drawn and labeled

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• The purpose is to show detailed cellular
  structures of a particular tissues or cell types,
  it is not necessary and time-consuming to draw a
  complete section through an organ in high power
• Dont draw too many cells! Draw their
  representatives or certain typical cells are
  usually adequate!

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• By all means imitate the style of the drawings in
  certain reference books, if that helps BUT
• DO NOT COPY THE DRAWINGS OR MEMORIZE THEM !

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Make a good drawing! Don't forget the rules!
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The End
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Orientation of sections
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Whole mount (w.m.)
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