DP Biology (last assessment 2024)
Question 18M.3.HL.TZ2.4b
| Date | May 2018 | Marks available | [Maximum mark: 3] | Reference code | 18M.3.HL.TZ2.4b |
| Level | HL | Paper | 3 | Time zone | TZ2 |
| Command term | Explain | Question number | b | Adapted from | N/A |
b.
[Maximum mark: 3]
18M.3.HL.TZ2.4b
Modification of neurons starts in the earliest stages of embryo development and continues to the final years of life. The image shows changes occurring in mice brain neurons at an early stage in life.
(b)
Explain neuroplasticity in terms of the developing neurons.
[3]
Markscheme
a. neurons that are stimulated develop more dendrites «than those not stimulated»
b. more dendrites allow for more synapses
c. developing neurons form multiple/new synapses
d. synapses that are stimulated/used many times are fortified
e. neural pruning involves the loss of unused neurons/synapses
f. plasticity of the nervous system allows it to change with environment/experience/to reorganize following damage
OR
some neurons can regenerate
