O-LevelBiologyTransport in Humans5090/22 · May/June 2014 · Q112 Marks
State three substances found in the urine of a healthy person.
- (a)State three substances found in the urine of a healthy person.[3]
- (b)The concentration of a person's urine can vary according to their diet. Explain how changes in a person's diet can affect the concentration of their urine.[4]
- (c)An investigation was carried out into the effect of diet on the rate of production of urine. Three students each took 1.5 dm³ of a different drink A, B or C. [Figure 1.1] shows the volume of urine released by each student over the next two and a half hours. Suggest which of the three drinks it would be better to avoid on a very hot day. Give an explanation for your answer.[5]
This question uses a diagram from the original paper, which isn't shown here. Open the full paper from the past papers archive to see it.
Mark scheme
Marking points from the official mark scheme (May/June 2014). The mark or mark type is shown in brackets.
- [3] 3 named substances, e.g. water
- salts/ions/named, e.g. Na⁺, CI¯, NH4+, Ca2+
- urea/nitrogenous waste/other named ;
- A any other 3 correct substances, e.g. hormones, pigments, enzymes
- R sugar/glucose
- A any three named ions for 3 marks
- A any three named nitrogenous waste products for 3 marks, e.g. creatinine, uric acid
- [4] more protein/ORA;
- correct ref. amino acids/ORA;
- broken down in/converted by liver/deamination ;
- less water/more salts/ions + in diet/ORA;
- (urine) more concentrated/more urea in (urine)/ORA ;
- Ig ref. to specific foods
- A ref. glucose/sugar only with ref. to diabetes
- [1] drink A;
- [4] increases volume of/more water in + urine/produces most/lot of/more urine ;
- water already being lost in sweat/AW;
- (sweating) more than usual ;
- ref. temperature regulation/to reduce body temperature/keep cool/AW;
- danger of dehydration / increases thirst / AW ;
- Mark independently of drink named
- Ig ref. heat loss in urine
Write your answer and get it marked
On Oracle Prep you can write or photograph your own answer and have it marked by AI against this mark scheme, with feedback on what you missed.
Sign up free →