Question 19M.3.SL.TZ2.b
| Date | May 2019 | Marks available | [Maximum mark: 3] | Reference code | 19M.3.SL.TZ2.b |
| Level | SL | Paper | 3 | Time zone | TZ2 |
| Command term | Explain | Question number | b | Adapted from | N/A |
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]
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.
[3]
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 ✔
In part (b) most candidates got 2 marks out of 3, as they failed to fully relate the concept of neural plasticity to learning.
