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

What is a defining characteristic of type one diabetes?

1. The pancreas produces excess insulin

2. The pancreas produces little or no insulin

3. The body becomes immune to glucagon

4. Insulin is overproduced as a response

The correct answer is: The pancreas produces little or no insulin

Type one diabetes is primarily characterized by the pancreas's inability to produce sufficient insulin, often due to the autoimmune destruction of insulin-producing beta cells within the pancreas. This lack of insulin means that glucose cannot effectively enter the body's cells, leading to elevated blood glucose levels. Individuals with type one diabetes require external sources of insulin to manage their blood sugar levels effectively. In contrast, other options refer to scenarios that do not accurately describe type one diabetes. The pancreas does not produce excess insulin, nor do individuals with this condition become immune to glucagon; instead, glucagon's role, which is to raise blood glucose levels, remains intact. There is also no overproduction of insulin as a response to any condition in type one diabetes. Therefore, the defining characteristic that highlights the state of insulin production is the pancreas producing little or no insulin.