DP Biology (last assessment 2024)
Question 19M.3.HL.TZ2.7
| Date | May 2019 | Marks available | [Maximum mark: 2] | Reference code | 19M.3.HL.TZ2.7 |
| Level | HL | Paper | 3 | Time zone | TZ2 |
| Command term | Outline | Question number | 7 | Adapted from | N/A |
7.
[Maximum mark: 2]
19M.3.HL.TZ2.7
Outline the process that could result in spina bifida during neural tube development.
[2]
Markscheme
a. neural tube formed by infolding of ectoderm/outer tissue layer ✔
b. «spina bifida» caused by «embryonic» neural tube not closing off completely ✔
c. « spina bifida» results in backbone vertebrae/spinal cord not closing/fusing properly ✔
Award marks for marking points in an annotated diagram.
Examiners report
Most candidates knew what spina bifida is but had a bit more difficulty expressing how it occurs using appropriate terminology. Many confused ectoderm with neural plate.
