| Date | May 2016 | Marks available | 1 | Reference code | 16M.3.SL.TZ0.4 |
| Level | Standard level | Paper | Paper 3 | Time zone | TZ0 |
| Command term | State | Question number | 4 | Adapted from | N/A |
Question
The diagram shows an advanced stage during neurulation in humans or chicks.
Label structures I and II
State the process by which neurons are initially produced in the embryo.
Outline the plasticity of the nervous system.
Markscheme
I: neural tube
II: notochord
Differentiation/neurogenesis «in the neural tube»
Plasticity allows the nervous system to adapt «structurally»
OR
plasticity allows cortical remapping/new connections
Neurons «axons» grow in response to stimulation/experience
Unused neurons die/are lost through pruning
Accept synapses in place of neurons
Examiners report
Question 4 was generally well answered. A few candidates had difficulty labelling the diagram of neurulation.
Question 4 was generally well answered.
Question 4 was generally well answered. Most could outline plasticity.
