Neco 2018 Biology Question 14

The diagram shows a labelled nephron of the human kidney, including Bowman's capsule, proximal convoluted tubule, descending limb of the loop of Henle, ascending limb of the loop of Henle, distal convoluted tubule and collecting duct. (a) Which segment is primarily responsible for the reabsorption of glucose from the filtrate? (b) Which part of the nephron creates the medullary osmotic gradient essential for urine concentration? (c) If the glomerular filtration rate is \(125\) mL min\(^{-1}\) and the plasma sodium concentration is \(140\) mmol L\(^{-1}\), and the proximal tubule reabsorbs \(65\)% of the filtered sodium, calculate the amount of sodium (in mmol min\(^{-1}\)) reabsorbed in the proximal tubule.