During dialysis, a membrane separates a patient's blood from the dialysis fluid. The concentration of mineral ions in the patient's blood is above normal. The dialysis fluid contains mineral ions at the normal blood concentration. Why does the concentration of mineral ions in the patient's blood decrease?
The dialysis membrane filters out only mineral ions that are present above the normal concentration.
The difference in concentration makes mineral ions leave the blood by osmosis through the dialysis membrane.
The dialysis membrane lets mineral ions cross from the blood side but blocks movement from the fluid side.
More mineral ions diffuse from the blood into the dialysis fluid than diffuse in the opposite direction.
85 exam-style questions on AQA GCSE Biology 5.3 Hormonal coordination in humans, covering 5.3.1 Human endocrine system, 5.3.2 Control of blood glucose concentration, 5.3.3 Maintaining water and nitrogen balance in the body, 5.3.4 Hormones in human reproduction, 5.3.5 Contraception, 5.3.6 The use of hormones to treat infertility (HT only), and 5.3.7 Negative feedback (HT only). Each one has a worked solution and a mark scheme showing where the marks go.