Date | May 2019 | Marks available | 2 | Reference code | 19M.3.SL.TZ2.4 |
Level | Standard level | Paper | Paper 3 | Time zone | Time zone 2 |
Command term | Describe | Question number | 4 | Adapted from | N/A |
Question
The performance of mice on a Barnes maze, shown in the photograph, was used to test the effect of cinnamon on learning.
Mice were trained for three days to find a compartment in the maze containing food. Their ability to find the compartment was tested by placing the mice at the centre and recording their movement. The mice were divided into two groups according to the route taken: good performers and poor performers. After this all the mice were fed a small amount of cinnamon in their diet for 30 days. They were then trained for three days and retested on the maze.
The diagrams show the movements of a typical good performer and a typical poor performer before and after cinnamon was included in their diet.
[Source: reprinted by permission from: Springer Natures, Journal of NeuroImmune Pharmacology, Cinnamon Converts Poor
Learning Mice to Good Learners: Implications for Memory Improvement, Khushbu K.Modi et al, copyright 2016]
Describe how the use of cinnamon changes mouse performance on the Barnes maze.
Scientists demonstrated that cinnamon increased neural plasticity in some parts of mouse brains. Explain how neural plasticity could have affected learning in poor performer mice.
It has been suggested that cinnamon might be of benefit to patients who are recovering from a stroke. Suggest one advantage of adding cinnamon to the diet of a patient who has suffered a stroke.
Markscheme
a. poor performers performed «much» better after a diet with cinnamon ✔
b. cinnamon made good performers perform slightly better/the same ✔
a. developing neurons form multiple synapses, so there are more connections between neurons ✔
b. synapses that are not used do not persist/neural pruning ✔
c. less synapses means there is less interference of stimuli / less background noise ✔
d. neurons/synapses that are used a lot are reinforced so information is accessed faster in neurons ✔
a. reorganization of brain function through plasticity «which is enhanced by cinnamon» ✔
b. cinnamon helps to form new neural pathways to replace the ones that were lost «due to the stroke» ✔
Examiners report
Describing how the use of cinnamon changes mouse performance on the maze was successfully answered.
In part (b) most candidates got 2 marks out of 3, as they failed to fully relate the concept of neural plasticity to learning.
In (c) most candidates suggested cinnamon helps to form new neural pathways to replace the ones lost due to a stroke.