In the data base questions of Paper 2 and 3, diagrams or images can be presented with specific objects to measure the linear length- organelles, stomata, diameter of lumen, .  You will need to be sure to have your own TRANSPARENT ruler in the exam room!   A transparent ruler is vital as this allows you to see through to the image and make the most appropriate placement of the ruler. Measurements should be as accurate as possible, although the IB gives a +/- window depending on the scale of the image.  You  must show the units  (mm or cm) for any measurement you make.  Measurements are more precise than an estimate.

Based on your measurement, you could be asked to make a calculation - magnification or actual size of the object, or 

deduce the role of the object based on your measurement or

suggest a reason for the importance of the measurement.

There are no specific assessment statements for measure but be prepared to identify specific structures indicated in the questions.

Measure the greatest width of the artery shown below. 

You would obviously need to know which object is the artery!


Command terms