DP Biology (last assessment 2024)
Question 23M.1.SL.TZ1.9
| Date | May 2023 | Marks available | [Maximum mark: 1] | Reference code | 23M.1.SL.TZ1.9 |
| Level | SL | Paper | 1 | Time zone | TZ1 |
| Command term | Question number | 9 | Adapted from | N/A |
9.
[Maximum mark: 1]
23M.1.SL.TZ1.9
Hemoglobin is a protein made up of two alpha and two beta polypeptide chains. In sickle cell anemia, a mutation causes one glutamic acid in each beta chain to be replaced by valine, as shown in the image.
[Source: AlphaFold Protein Structure Database, n.d. [image online]
Available at: https://alphafold.ebi.ac.uk/entry/P68871
[Accessed 14 March 2022]. Public domain.]
How does this mutation in hemoglobin cause sickle cell anemia?
A. It prevents the beta chains from forming a protein.
B. It replaces an amino acid with a fatty acid in the beta chain.
C. It changes the three-dimensional conformation of hemoglobin.
D. The polypeptide produced in sickle hemoglobin is shorter than in normal hemoglobin.
[1]
Markscheme
C