Biology 332 - Protistology Term 2 - 2002-2003

 

Drawings for laboratory reports

What makes a good drawing

Here is a good drawing of an Amoeba proteus cell drawn live. This image is slightly less than full size.

amoeba1.jpg (68264 bytes)

What makes this drawing good. Accuracy; it actually looks like the specimen. Anyone can recognize it. all major parts of the organism are clearly and ccurately portrayed. The major parts of the cell are clearly labeled. Notice that not all of the detail is shown. The finer details are filled in in only part of the drawing.   This is OK. There is enough to give the viewer a good idea of the appearance of the cell. As this was an observation on a living specimen, it is important that patterns of movement are noted. This could have been done a bit more clearly, for example, indicating the pattern of cytoplasm out of the uroid portion of the cell, as well as the patern of flow in the oldest of the pseudopodia.

Notice the use of lables and marginal notes. These are important.

Why was the mark on this drawing 8.5 and not higher? The contractile vacuole was plainly visible in these specimens and was missed. It is usually located in the region between the nucleus and the uroid. As mentioned bove, the pattern of cytoplasmic movement might have been dealt with in a more complete manner.

For comparison, here is another drawing, below, of the same species that is not so good. This drawing lacks detail. A good point is the indication of the direction of cytoplasm movement. The designation of the nucleus is incorrect. This is close to the minimum acceptable standard s you can tell by the mark assigned. The mark is as high as it is because the labeling is largely correct. It is not particularly clear what the student saw, or that it was interpreted correctly.

amoeba2.jpg (22817 bytes)

What is the difference? The difference in is realism, clarity and accuracy. Notice that the mark for this drawing is not a 5. There are some good features. It is relatively carefully done. The lines are clear and firm, structures are labeled, even if wrong, curves are closed. While not particularly good, this work is not careless or slipshod. There is clearly some observation behind it, as well as a fair amount of care in its execution.

The following pair of drawings are of a stained Arcella specimen. The dark granular material in the drawing below is the chromidial net, a massive construction of rough endoplasmic reticulum that is involved in synthesis of proteins to form the text for the next generation. The two round bodies with dark centres are nuclei.

arcella1.jpg (30669 bytes)

This drawing above is really quite good. The nuclei, coromidial net and the test are well drawn. Notice, however that the nuclei and the endosome within the nucleus is not labeled. The chromidial net and the test are properly labeled. Better labeling would have resulted in a higher mark for this drawing

arcella2.jpg (26465 bytes)

This drawing is not as good. The labeling is potentially better than in the drawing above, but some of the structures are improperly interpreted (e.g. secretory granules). The drawing lacks detail and is not particlarly easy to interpret. As you can see this was given a mark of 7/10.

Below we have a well labeled drawing of Acanthamoeba.

acanthamoeba1.jpg (36933 bytes)

Here is another drawing of a different specimen of Acanthamoeba. This drawing would win no prise for artistic merit. That is, however, only a secondary issue. It is basically correct and is correctly labeled, even though it lacks detail.

acanthamoeba2.jpg (23250 bytes)