DP Biology (last assessment 2024)
Question 17N.2.HL.TZ0.03
| Date | November 2017 | Marks available | [Maximum mark: 3] | Reference code | 17N.2.HL.TZ0.03 |
| Level | HL | Paper | 2 | Time zone | TZ0 |
| Command term | Describe | Question number | 03 | Adapted from | N/A |
03.
[Maximum mark: 3]
17N.2.HL.TZ0.03
(c)
Describe the role of ADH in human osmoregulation.
[3]
Markscheme
a. secreted when blood/plasma is hypertonic/too concentrated/water content too low
b. makes walls of collecting duct/distal convoluted tubule «more» permeable to water
c. more aquaporins in membranes «of collecting duct cells»
d. more water reabsorbed from filtrate/from urine/more water returned to blood
e. small volume of concentrated urine excreted
[Max 3 Marks]
