OCR General Certificate of Secondary Education (GCSE) Biology Practice Exam

Disable ads (and more) with a membership for a one time $2.99 payment

Prepare for the OCR GCSE Biology Exam with our comprehensive study resources. Practice with quizzes, flashcards, and detailed explanations to enhance your understanding. Ace your exam and secure your academic success!

Each practice test/flash card set has 50 randomly selected questions from a bank of over 500. You'll get a new set of questions each time!

Practice this question and more.

What happens to the brain's active areas during an MRI scan?

They become less bright on the scan
They light up due to increased blood flow
They cool down rapidly
They shrink in size

The correct answer is: They light up due to increased blood flow

During an MRI scan, active areas in the brain demonstrate increased brightness due to heightened blood flow. This relationship is rooted in the fact that areas of the brain that are engaged in specific tasks require more oxygen and nutrients, which are delivered through increased blood circulation. As a result, the enhanced blood flow to these regions causes a change in signal that the MRI detects, resulting in those areas appearing brighter on the scan. This principle is utilized in functional MRI (fMRI), which measures brain activity by detecting changes associated with blood flow. Therefore, the brightness on the scan is a direct indicator of the brain regions that are currently active or working harder than others, clearly linking brain function to blood flow dynamics.