Question 23M.3.SL.TZ2.4
| Date | May 2023 | Marks available | [Maximum mark: 3] | Reference code | 23M.3.SL.TZ2.4 |
| Level | SL | Paper | 3 | Time zone | TZ2 |
| Command term | Outline, State | Question number | 4 | Adapted from | N/A |
The images show two stages of a process in the development of embryonic tissue in Xenopus.
[Source: Used with permission of Elsevier Science & Technology Journals, from Development of the Nervous System,
Dan H. Sanes, Thomas A. Reh, William A. Harris, Matthias Landgraf, 4th Edition, 2019;
permission conveyed through Copyright Clearance Center, Inc.]
State the two structures indicated by X and Y on the images.
X:
Y:
[2]
- X: neural fold/groove;
- Y: notochord;
Most stronger candidates could identify the two structures indicated on the images of the embryonictissue in Xenopus. Some candidates mentioned the neural plate instead of groove. The question asks candidates to identify structures, not tissue, so ectoderm was not accepted as a correct response.
The image shows one stage of early development of a neuron in an embryo.
[Source: Boulan, B., Beghin, A., Ravanello, C., Deloulme, J.-C., Gory-Fauré, S., Andrieux, A., Brocard, J. and Denarier, E.,
2020. [AutoNeuriteJ]. PLOS ONE 15(7) [e-journal] Available at:
https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0234529
[Accessed 1 April 2021].]
Outline one essential process that occurs during the development of neurons in an embryo.
[1]
- development/growth of dendrites;
- development/growth of axon;
- migration to other parts of the embryo/to final location;
In (b) many referred to the development of the nervous system and not the neuron as required.