Do your students ever complain that they hadn't been taught the content of a question in your test?  The chances are that the question is testing Aim 4. To develop an ability to analyse, evaluate and synthesize scientific information.  Students often struggle to get started when they are asked to use their knoweldge in a new context.

In the IB guide the following assessment objectives often lead to questions which cover material from more than one topic.

1. Apply facts, concepts and terminology.
2. Formulate, analyse and evaluate: hypotheses, research questions, predictions and scientific explanations.

These questions usually contain some new information described briefly at in the question.
Students have to identify relevent areas of biological knowledge and then apply them to the question.

One method of helping students to cope with these questions is to model the steps required to solve puzzling, questions. Having a simple structure in mind help to make the explanation clear, and makes learning a strategy for such questions easier for students to remember.

An example

Imagine a question like this, which covers material from the Cells topic, Molecules topic and the Humans topic, All SL.

How should a student begin to answer the question?

The following four steps would make a good method for this sort of question. I like to show this approach to students and to regularly remind them of step 4.  So often the IB mark scheme requires students to link a cause with an effect or a structure with a function before the awarding of a mark.

1. First dissect the question, looking for key words.
2. Then quickly summarise the meaning of these key words: osmosis, liver cells, glucose, glycoge, soluble, insoluble.
3. Try to find simple explanations that are known already.
4. Then 'storyfy' the answer Define --> Cause --> Effect --> Consequence

This is how the whiteboard looked after one such explanation...