Drawing techniques P.1
BIOLOGY TAS guide (III)
DOs and DON'Ts in making Biological drawings:
A)
Notes on biological drawings
The making of accurate drawings is an essential skill for Advanced level biology
students. Students are required to make drawings of external features of whole specimens,
parts of specimens, dissections and prepared slides.
Students should not the following points:
1. A drawing should be genuine and accurate record of what has been seen. DO NOT copy
diagrams from books with little resemblance to the specimen, dissection or prepared slide
under investigation.
2. For low power drawings, only the outline of the structures or tissues needs to be drawn. DO
NOT draw Individual cells, they are required only for high power drawings.
3. Draw with bold, fark, smooth lines. Shading and the use of crayons are not encouraged.
4. Avoid making drawings on both sides of a paper.
5. In making a drawing, first decide what you want to show. Then plan your drawing to fit on
the page. it is imporant that the various parts of the structures are drawn in proportion.
6. Drawings should be large, neat and tidy.
7. All relevant structures should be fully and clearly labelled using pencil. Each label should be
connected to the appropriate part of the drawing by a clear labelling line. The labelling lines
should run as horizontal as possible and should not intersect with one another. Do not
label too close to the drawings, and do not writeon the drawing itself. Distribute the labels
well around the drawing so that the labelling lines can be kept reasonably short.
8. Every drawing should include a title, the magnification power, and the plan of view of the
specimen (such as transverse section, longitudinal section).
9. Make additional drawings if important details are too small to be shown in a low power
drawing. this can be done by making a simple drawing of the main features, and other
drawings on details of small parts only. for examples, the recording of a transverse section of
a stem should include a low power plan of the section and high power drawings of different
cells types as requried to show the detail of the cells.
10. If suffices to show the internal structural details in a small representative sector of the
specimen which shows repetitive features.
11. It is sometimes appropriate to make short notes close to the labels. Such annotated
drawings are particularly valuable as they combine a record of structures with related
functions and/or biological interests.
Note : High power magnification means the use of the 40X or 60X objective lens and the total magnification
power up to 400X to 600X. The purpose of these drawings is to show the cell details.
.
Low power magnification means the use of the 10X or lower objective lens and the total magnification
power not beyond 100X. The purpose of these drawings is to show the arrangement of tissues in the
structure.
.
Whole mount specimen means to observe with the naked eyes only.
B)
Dos and Don’ts
Drawing techniques P.2
Dos
Don’ts
1.
Always use a pencil, and a pencil only, for the Do not use ink, or colour, or ball-pen.
drawing, the labels, the title – everything
2.
Use an HB pencil. It is neither too hard nor too
soft.
3.
Use a good quality eraser.
4.
Your drawing should be a plain line drawing.
Do not shade or blacken structures, such as the nuclei.
Do not use shading to create 3-D effects. Biological
drawings are generally 2-D drawings (flat).
5.
Always draw boundary lines free-hand.
Do not draw a cell with ruler or compass even when
the cells have very regular shape.
6.
Lines should be single, thin, firm from the Do not draw lines of uneven thickness, lines that fade
beginning to the end, evenly dark.
out, and Do not go over the same line two or more
times.
7.
Lines should be continuous and should join Do not leave meaningless gaps or have lines crossing
for no reason at all.
neatly.
8.
Lines should be reasonably steady, straight:
9.
Centralize your drawing well and make the most Do not cram too many drawings, often of unrelated
of the available drawing space.
things, on the same page. On the other hand, Do not
push everything into one corner and leave most of the
page unused. See how much you have to draw and
label, and lay out your drawing accordingly.
10. To draw straight guide-lines always use a
transparent plastic ruler with undented edges.
Do not draw shaky, wavy lines:
Do not draw guide-lines free-hand, even when they
are very short.
11. Guide-lines should be
straight, plain, and Do not tip guide-lines with arrows:
whenever possible, horizontal.
12. Distribute your labels well around the drawing
so that guide-lines can be kept reasonably short.
Do not make guide-lines exceedingly long and Do not
have too many guide-lines crossing your drawing.
13. The gap between the end of the guide-line and the
label should be short, say 2mm.
14. The other end of the guideline should touch the
part you wish to label:
15. Use a simple kind of print when you label:
16. Labels should be concise (unless otherwise stated,
Do not leave a large gap; Do not stop short of the
structure you label:
Do not use the cursory form and Do not use capital
letters in labeling:
Do not underline labels or place the label above the
e.g. for annotated diagrams) and should fit into guide-line:
one line:
Drawing techniques P.3
17. Always give a title.
Use the words of the Do not give a name to a specimen, even if you know
it. You could be wrong! If something is referred as
question to phrase your title.
specimen A and you conclude from your observation
that it is, say a T.S. of a root, Do not call it " T.S. of a
root ". The title should be " T.S. of specimen A ".
Give a name only when you are asked to identify the
specimen.
18. Write the title at about 2cm below the drawing.
Do not place the title at an ambiguous position, such
as mid-way between two drawings.
19. By all means imitate the style of the drawings in
DO NOT COPY THE DRAWINGS OR
MEMORIZE THEM
your books.
C)
TAS Sample drawings
20. Making Low-power drawings:


Show the tissue layout / draw the whole or a representative part of the section to show the relative
position of different types of tissues
When making 'Low Power' drawings, NO individual cells should be drawn.
Drawing techniques P.4
21. Making HP drawings:

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;

Don’t draw too many cells! Draw their representatives or certain typical cells are usually adequate
Sample marking
22. Drawing of whole mount specimen(w.m.)


means to observe with the naked eyes only.
Drawing techniques P.5
A3 : 1
Reason

Title is missing. This drawing shows poor resemblance to the specimen and is done rather casually.
However most of the important biological features are shown. Segmentation in the abdomen, a feature
which can be observed, is missing. Antennae, mouthparts and legs are poorly drawn.

Lines can be smoother.

Though labels are correct, marks given should not be based mechanically on the number of correct
labels alone, but should rather base on an overall impression of the drawing as a whole.
ugh magnification is shown.
A3 : 3
Reason

This drawing shows a moderate degree of resemblance to the specimen.

Important biological features are shown. The proportion of the legs to the rest of the body is not accurate.
The antennae, look broken, should be stated as such or indicated by broken line. Some details of the
legs, e.g. segments, claws, pads, spurts, etc. are missing.

Lines are clear and mostly steady though slightly too thick.

Labels are appropriate except that the region for thorax should be extended to cover those thoracic
segments where the legs arise.

The title should specify that the "lateral view" not the "lateral surface" of the grasshopper is being drawn.
Drawing techniques P.6
A3 : 5
Reason

It shows a high degree of resemblance to the specimen.

Important biological features are shown. The shape and the proportions of various parts are good.

Most labels are correct.

Lines are clear and smooth.

Title and magnification are appropriate.
Drawing techniques P.7
Low-power drawing of T.S. Ileum
First diagram A3 : 4
Reaso The drawing shows an acceptable degree of resemblance to the specimen. The four layers of the
n
ileum wall are clearly shown. The proportion of the various layers are acceptable except that the
muscularis mucosa is a bit thick.
Double lines should be used to show the thickness of the wall of the blood vessels.
Labels are neatly arranged but the mucosa is not labelled. They could have been grouped to show the
four basic layers.
The title and magnification are appropriate.
Drawing techniques P.8
Second diagram A3 : 3
Reason This drawing shows good resemblance to the slide of the ileum with good proportion of the various
layers.
The dots in the submucosa could have been drawn better. Circles should not be used in the longitudinal
layer. Cell, e.g. goblet cell and its label should not be shown in L.P. drawings.
Label lines should not cross : line for villi and lacteal. Labels such as the "columnar epithelium mucus
membrane" and "the smooth muscle layer" are intercepted by long bracket of the mucosa. In general,
labels are a bit crowded on the right-hand side. There are a number of wrong labels : the circular muscle
had been wrongly identified as the longitudinal muscle and the longitudinal muscle had been wrongly
identified as the serosa. Certain features in the submucosa was wrongly labelled as the circular muscle
layer.
The title can be bigger. Perhaps a smaller section of ileum wall should be drawn to avoid too much
detail in the drawing.
Drawing techniques P.9
Third diagram A3 : 1
Reason
This drawing is like a sketch and shows little resemblance to the specimen. The four layers : mucosa,
submucosa, muscularis externa and serosa are not clearly shown by lines.
No biological details such as blood vessels and the two muscle layers have been included.
The labels are neatly arranged.
The title is spelled wrongly. It is not informative as to indicate how the ileum has been sectioned to give the
view shown.
Drawing techniques P.10
Marking and reasons:
First diagram A3 : 2
Reason Some of the labels are missing.
Poor resemblance.
Poor drawing on blood vessels.
Drawing techniques P.11
Second diagram A3 : 4
Reason
Good resemblance. Spreaded lines.
Enough labels.
No magnification.
Good scale.
Hepatic portal vein is too thick.
No anus.
Drawing techniques P.12
Third diagram A3 : 3
Reason Good resemblance,.
Good scale,
Labels are too close to the drawing,
The lines are not smooth enough.
The shape of liver is not true.
The stomach is too large
Good labels,
End