DP Biology (last assessment 2024)
Question 18M.3.SL.TZ2.18
| Date | May 2018 | Marks available | [Maximum mark: 4] | Reference code | 18M.3.SL.TZ2.18 |
| Level | SL | Paper | 3 | Time zone | TZ2 |
| Command term | Explain | Question number | 18 | Adapted from | N/A |
18.
[Maximum mark: 4]
18M.3.SL.TZ2.18
Explain the stages involved in the recycling of erythrocytes by the liver.
[4]
Markscheme
a. phagocytosis of erythrocytes by Kupffer cells
b. hemoglobin is split into globin and heme group
c. globin is hydrolysed to amino acids
d. amino acids used in protein synthesis
e. heme group broken down into iron and bilirubin
f. iron is (carried back to the bone marrow to be) used for production of new erythrocytes
g. bilirubin is secreted into bile
In b. both globin and heme required.
In e. both iron and bilirubin required.
Examiners report
