Homeostasis controls the internal conditions of the body - AQA - GCSE Biology - Question 9 - 2018 - Paper 1

There are two main types of diabetes:

1. Type 1 Diabetes: This type is caused by the immune system attacking and destroying insulin-producing beta cells in the pancreas, leading to little or no insulin production. Treatment typically involves daily insulin injections or the use of an insulin pump.

2. Type 2 Diabetes: This type is often related to insulin resistance, where cells do not respond effectively to insulin, often associated with obesity and inactivity. Treatment includes lifestyle changes such as diet and exercise, along with medications that improve insulin sensitivity or promote insulin secretion.

To find the percentage of the UK population estimated to have diabetes, we need to calculate the total number of people with diabetes (both diagnosed and undiagnosed) and then divide that by the total population:

• Total diagnosed diabetes: $3.45 \times 10^6$

• Estimated undiagnosed diabetes: $5.49 \times 10^5$

• Total with diabetes: $3.45 \times 10^6 + 5.49 \times 10^5 = 4.0 \times 10^6$

• Total population in 2015: $6.5 \times 10^7$

• Now, calculate the percentage: $\frac{4.0 \times 10^6}{6.5 \times 10^7} \times 100 \approx 6.15\%$

Rounding to two significant figures gives 6.2%.

A blood test is more reliable than a urine test because:

1. Blood glucose levels can be precisely measured, reflecting current and accurate blood glucose concentrations.
2. In contrast, urine tests may yield false negatives or positives, as glucose might not be present in urine unless levels are very high, which may not indicate the current state of blood glucose.

Patients are not allowed to eat for 8 hours prior to the glucose tolerance test to ensure that the results reflect the body's response to the glucose drink without interference from other food that could already be affecting blood glucose levels. This fasting period allows for a controlled starting point for accurate testing.

Patient A has diabetes. This is indicated by the consistently high blood glucose levels observed after consuming the glucose drink, failing to return to baseline levels within the test duration. In contrast, Patient B's glucose levels rise but subsequently drop closer to baseline, indicating a more normal response to glucose.