DP Biology (last assessment 2024)
Question 23M.1.HL.TZ2.38
Date | May 2023 | Marks available | [Maximum mark: 1] | Reference code | 23M.1.HL.TZ2.38 |
Level | HL | Paper | 1 | Time zone | TZ2 |
Command term | Question number | 38 | Adapted from | N/A |
38.
[Maximum mark: 1]
23M.1.HL.TZ2.38
Where is the greatest quantity of water reabsorbed from the nephron?
A. Bowman’s capsule
B. Proximal convoluted tubule
C. Loop of Henle
D. Collecting duct
[1]
Markscheme
B
Examiners report
This question on reabsorption of water in the kidney was difficult for all students. The guide states that the proximal convoluted tubule selectively reabsorbs useful substances by active transport, and it was assumed that the students would deduce that this is coupled by the passive movement of water. This assumption proved wrong, and the question discriminated very badly with nearly all the stronger candidates opting for the Loop of Henle as their response.