Biological Drawings And He said, Let us make man to our image and likeness Genesis 1:26

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1 Biological Drawings And He said, Let us make man to our image and likeness Genesis 1:26 For we say that an image is like or unlike what it represents, according as the representation is perfect or imperfect But likeness may be considered in another way, as signifying the expression and perfection of the image. Summa Theologica Q93:A9 Introduction In biology, you may often be asked to draw what you observe. A person does not need to be a great artist in order to make a correct biological drawing. A biological drawing is meant to be an accurate image and a permanent record of the life form, or life process, observed. This is different than art from a drawing made from memory, a drawing that may be embellished, abstract or realistic, drawn with different sorts of media, or subject to the interpretation of the artist or the viewer. A biological drawing should only be drawn while observing the specimen, not from memory. It should be drawn with a sharp pencil lines on a white sheet of paper, without shading or sketching. The specimen should be looked at every few seconds to make sure that the drawing is accurate and precise. Any mistakes should be erased and corrected. It may be tempting to become overwhelmed with specimens with a great amount of detail and in response, to rush through a drawing. However, it is important to draw each cell exactly how it looks. But, it is not always necessary to draw the entire specimen. You may select a smaller portion of the specimen and draw it completely. Learning Objectives: Accurately produce and label biological drawings Identify mistakes in poorly-made drawings Materials Required: From Biology Kit Student Supplied Ruler Pencils Safety Rulers may have sharp edges. Do not allow small children to play with them. Handle with care. Rules for Biological Drawings: TECHNIQUE: Look at the specimen every few seconds as you are drawing. Never draw from memory, but while looking at the specimen. Drawing at a location away from your specimen violates scientific integrity ACCURACY: Draw what is there, not what you think should be there. Do not idealize the diagram or drawing, it should represent reality. Proportions should be accurate. If necessary, measure lengths or place an object in the field of vision (such as a quarter) for comparison Catholic Initiatives in Math and Science, LLC All Rights Reserved 1

2 MATERIALS: Draw on white, unlined paper with a #2H pencil. Use a clean eraser for mistakes. Pens are not acceptable because they cannot be erased. STYLE: Drawings and/or diagrams should be simple with clean lines. Do not sketch. Do not shade the drawing. If you wish to show a darker area, use stipples (dotting) SIZE: Drawings should be large enough to show all the parts without crowding. The greater the number of parts, the larger the drawing should be. A good rule of thumb is to start at half a page in length for a drawing. You do NOT have to show everything. Often, a small cross-section of the specimen will suffice. Most plant and animal tissues are made up of individual cells. When you show one representative cell, make sure to include the cell boundaries of the surrounding cells. POSITIONING: Start the drawing just to the left of center of the page, saving the right-hand side for the labels. Do not draw in the corner LABELS: Leave a good margin for labels. Use the ruler for label lines. Label lines should never cross. Keep the labeling lines either horizontal or vertical. ALWAYS include the following: o Title Place this at the top unless your instructor advises differently o Magnification (usually in title) or Scale below specimen o Names of known or identifiable structures with lines connecting the structures to their labels o Movement noted in living specimens. Experiment Remember, you do not need to be an artist to render a useful diagram or drawing. The purpose is to make a permanent record of what you have observed when examining a specimen. When drawing a specimen, you are forced to observe carefully and closely. Before turning in a drawing, make sure you know what every line represents. If you do not, look more carefully at the specimen. 1. Review the acceptable biological drawing of a whole organism to the right: Note the title above and the author and date below. Your own instructor may ask you to place the title and scale below the diagram or give other specific directions. This is perfectly acceptable. The size of the specimen is represented by a scale and is placed below the diagram. Scale is indicated by stating how many times larger the specimen has been drawn. Labels are not crossing, but are all horizontal 2. Review the acceptable biological drawing of a microscopic organism below: Note the title above the figure. Note that the magnification through which the specimen was viewed is in the title. The author s name and date is below. Your particular instructor may ask you to specifically place the title with magnification below the diagram. This is perfectly acceptable. Labels are not crossing but are all horizontal. If necessary, they may be vertical as well, but never crossing Catholic Initiatives in Math and Science, LLC All Rights Reserved 2

3 It is not necessary to draw everything on a slide. Rather, you may choose to draw a representative cross-section of cells. As few as 2 to 4 are sufficient to show their structure and how they arranged. Notice how portions of adjacent cells are shown. 3. Now that you have reviewed the rules for making biological drawings and have seen some good examples, proceed to the lab report Catholic Initiatives in Math and Science, LLC All Rights Reserved 3

4 Lab Report for: Specimen Used for Biological Drawing: The photograph to the left is a light microscope view of an onion root tip from Allium cepa. Onion root tips are often studied to visualize cells undergoing mitosis (cellular division). 1. The drawing below was submitted when a teacher asked for the class to view this slide under the microscope and to label the pertinent parts Catholic Initiatives in Math and Science, LLC All Rights Reserved 4

5 Identify and describe 8 unacceptable features of the student s biological diagram. a) b) c) d) e) f) g) h) 2. In the space below, attempt your own version of a biological drawing based on the photograph of the onion root tip. Make a point of correcting all the mistakes you have identified in the sample student s attempt and follow the instructions in the lab protocol. If necessary, you may draw on a separate sheet of paper. Then you can scan, photograph, , print, upload to Dropbox, or give to your instructor in any manner he or she indicates. 3. Why are careful, accurate biological drawings more valuable to a scientific investigation than an artistic approach? 2016 Catholic Initiatives in Math and Science, LLC All Rights Reserved 5