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

What occurs when blood glucose levels are too high?

1. Cells receive insufficient energy

2. Glucose is excreted through urine

3. Insulin levels drop significantly

4. Blood pressure increases

The correct answer is: Glucose is excreted through urine

When blood glucose levels rise above the normal range, the body responds by excreting excess glucose through the urine. This process occurs because the kidneys filter blood and, when glucose levels exceed a certain threshold, they cannot reabsorb all of it. As a result, glucose is allowed to pass into the urine, which may lead to a condition known as glucosuria. This mechanism serves as a way for the body to regulate high blood sugar levels and prevent potential damage to organs and tissues caused by prolonged hyperglycemia. The other options do not accurately describe what primarily occurs when blood glucose is too high; for example, insufficient energy in cells relates to low glucose levels, while insulin levels actually rise to help lower blood glucose, and high blood pressure is not a direct result of elevated glucose.