A CT scan shows no obvious change in the structure of a brain region. A PET scan shows much lower activity in that region than in a healthy comparison group performing the same task.
Which conclusion is justified?
the CT result proves that every neurone in the region has stopped transmitting impulses
brain function must be normal because this CT scan shows no visible structural change
brain function can be reduced without a structural change visible on this CT scan
the PET result must be incorrect because structural and functional scans are identical
43 exam-style questions on Edexcel GCSE Biology 2.3 The nervous system and brain, covering 2.3.1 Structures and functions of the brain, 2.3.2 Imaging brain function with scanning, 2.3.3 Limitations in treating nervous system damage, 2.3.4 Neurones and impulse transmission, and 2.3.5 Structure and function of a reflex arc. Each one has a worked solution and a mark scheme showing where the marks go.