For each experiment, identify the following: What is being tested and why? What are the variables, and what factors stay the same? In this example, the mass of the dialysis bags changes with the variable of sucrose concentration. Changes in mass can only come from water entering or leaving the bags, so the question deals with osmosis. (You'll learn all about osmosis, diffusion, and transport over membranes in the chapter covering the cell.)

 

    The three sample questions are good examples of the various types of questions the SAT II Biology asks in experiment groups. You don't have to know anything about concentrations, osmosis, or membrane transport to answer the first question in this group; determining percent change in mass demands only simple data interpretation. The second question requires you to extrapolate and make predictions from the data. The third question asks you to make predictions on what would occur if the experiment were slightly modified. This last type of question goes beyond the numbers and requires knowledge of the topic. If you can identify the general biological properties of the experiment in advance, you should have no trouble answering questions of this sort. The answers to the above sample questions are: 8 D, 9 D, and 10 C.

 

    The SAT II Biology may also present data in graph form. For graphs, make sure you know what the axes represent. Think about what relationship exists between these concepts and identify in advance any general trends you can think of. If it helps, sketch out your own tables or notes to sort the data and identify trends or exceptions. For all experiment-based questions, elimination is a helpful tool. You can eliminate answer choices that do not relate to the experiment's variables or what is being tested, or those choices that contradict your knowledge of the biological principles working in the experiment or scenario.