The kidneys remove wastes from the blood, separate useful molecules from excretory products, and regulate the water content of blood.
Fig. 2.1 shows a kidney tubule together with the blood vessels associated with it. The arrows indicate the direction in which blood flows.
Fig. 2.2 shows a drawing of a vertical section through a cell from the lining of region 2 of the tubule.
(a(i))[1]
State what structure P is called.
(a(ii))[1]
Suggest the reason.
(a(iii))[2]
Explain why the microvilli on the surface of these cells are important.
(b)[6]
Outline how the kidney tubules work to produce urine from the substances in blood plasma. Support your answer with information from Fig. 2.1, Fig. 2.2 and Table 2.1.
(c(i))[1]
State the term used for maintaining a constant internal environment by negative feedback.
(c(ii))[3]
Explain how negative feedback regulates the blood glucose concentration of a person who has not eaten for a day.
Worked solution & mark scheme
This 14-mark question has a full step-by-step worked solution and mark scheme. One marking point: “glomerulus” …