Date | November 2016 | Marks available | 4 | Reference code | 16N.3.SL.TZ0.18 |
Level | Standard level | Paper | Paper 3 | Time zone | TZ0 / no time zone |
Command term | Explain | Question number | 18 | Adapted from | N/A |
Question
The micrograph shows a section through the human liver.
The cell labelled X is only found in the liver and is associated with the wall of a sinusoid.
(i) Identify cell X.
(ii) Outline the function of cell X.
Explain the importance of bilirubin in the onset of jaundice.
Markscheme
(i) Kupffer cell
(ii)
a. they are macrophages/phagocytes
b. break down red blood cells
c. separates heme (group) from (protein) globin chain
There is no ECF here.
a. «jaundice is» a yellowish pigmentation of the skin/whites of eyes
b. caused by high levels of bilirubin in blood/tissues
Simply stating “caused by high levels of bilirubin” is not enough for marking point b. However “tissues” may be implied as part of the answer to marking point a.
c. comes from breakdown of red blood cells
d. results from the breakdown of the heme group of hemoglobin
e. released into blood when excess is produced
f. released into blood when bile ducts blocked
g. normally excreted with bile
h. jaundice is often seen in liver disease such as hepatitis/liver cancer/chronic alcoholism/cirrhosis
OR
newborn/neonatal jaundice «due to immature liver»