Question 19M.3.HL.TZ1.a
| Date | May 2019 | Marks available | [Maximum mark: 3] | Reference code | 19M.3.HL.TZ1.a |
| Level | HL | Paper | 3 | Time zone | TZ1 |
| Command term | Describe | Question number | a | Adapted from | N/A |
The diagram shows part of the embryonic development in a clawed toad of the genus Xenopus.
[Source: © International Baccalaureate Organization 2019]
Describe the process occurring in the diagram.
[3]
a. the process is neurulation ✔
b. ectoderm tissue differentiates to form the neural plate ✔
c. the neural plate «changes shape and» folds ✔
d. «the ends join» to form the neural tube ✔
This question was fairly well answered by most candidates, and it appears that the process of neurulation is covered well by teachers choosing this option. However, as stated before, students struggled to communicate the process clearly, finding it hard to delineate the steps in an organised, sequential manner. There was also some confusion among weaker students regarding the three primary germ layers during embryonic development – all three layers were suggested by these students. They also used subject-specific terminology such as “neural plate,” “neural fold” and “neural tube” incorrectly.
