Question 22M.1A.SL.TZ1.22
| Date | May 2022 | Marks available | [Maximum mark: 1] | Reference code | 22M.1A.SL.TZ1.22 |
| Level | SL | Paper | 1A | Time zone | TZ1 |
| Command term | Question number | 22 | Adapted from | N/A |
Blood clotting involves a cascade of reactions. Which statement describes the blood-clotting process?
A. Red blood cells release clotting factors that result in the production of fibrin.
B. Clotting factors trigger the conversion of the inactive thrombin to prothrombin.
C. Insoluble fibrinogen is converted into soluble fibrin.
D. Fibrin forms a mesh that traps platelets and blood cells.
[1]
D
About half of candidates answered this question correctly, but the discrimination index was rather low. Answer D was clearly correct, but many candidates chose A or B instead. A was incorrect because red blood cells do not release clotting factors. B was incorrect because thrombin is not converted to prothrombin. As ever, candidates are advised to read all the possible choices.
