A volunteer has two PET scans. During the first scan, the volunteer solves number puzzles. During the second scan, the volunteer rests with their eyes closed. Brain region P has lower tracer uptake during the first scan than during the second scan.
Which conclusion is supported by these results?
The scans indicate greater activity in region P during the puzzles, but they do not establish whether the region is needed for the task.
The scans indicate that region P was inactive during the puzzles, but they do not establish whether the region is active during other tasks.
The scans indicate lower activity in region P during the puzzles, which suggests the region is probably unnecessary for solving number puzzles.
The scans indicate lower activity in region P during the puzzles, but they do not establish that the puzzles caused this difference.
111 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.