DP Biology (last assessment 2024)
Question 19N.3.SL.TZ0.4d
Date | November 2019 | Marks available | [Maximum mark: 2] | Reference code | 19N.3.SL.TZ0.4d |
Level | SL | Paper | 3 | Time zone | TZ0 |
Command term | Explain | Question number | d | Adapted from | N/A |
d.
[Maximum mark: 2]
19N.3.SL.TZ0.4d
The development of the neural tube in the frog Xenopus is shown in the diagram.
[Source: reprinted by permission from Nature Reviews Neuroscience, Gammill, L., Bronner-Fraser, M.
Neural crest specification: migrating into genomics. Nat Rev Neurosci 4, 795–805 (2003) doi:10.1038/nrn1219]
(d)
Explain how the nervous system develops from the cells of the neural tube.
[2]
Markscheme
a. neurons differentiate from neural tube / stem cells ✔
b. axons/dendrites grow ✔
c. «axon growth is» directed by chemicals/growth substances ✔
d. neurons migrate ✔
e. synapses form ✔
