Question 22M.1A.SL.TZ2.2
| Date | May 2022 | Marks available | [Maximum mark: 1] | Reference code | 22M.1A.SL.TZ2.2 |
| Level | SL | Paper | 1A | Time zone | TZ2 |
| Command term | Question number | 2 | Adapted from | N/A |
Red blood cells from a small mammal were immersed in NaCl (sodium chloride) solutions of different concentrations for 2 hours. The graph shows the percentage of hemolysed (ruptured) red blood cells at each concentration.
[Source: Zaidan, T. , de Matos, W. , Machado, É. , Junqueira, T. , Vicentini, S. , Presta, G. and Santos-Filho, S. (2010)
Cellular effects of an aqueous solution of Losartan® on the survival of Escherichia coli AB1157 in the presence
and absence of SnCl2, and on the physiological property (osmotic fragility) of the erytrocyte. Advances
in Bioscience and Biotechnology, 1, 300–304. doi: 10.4236/abb.2010.14039. Available at https://www.scirp.org/pdf/ABB20100400005_18844979.pdf Licensed under a Creative
Commons Attribution 4.0 International License (https://creativecommons.org/licenses/by/4.0/).]
What can be deduced from the graph?
A. At Y, the net movement of Na ions between red blood cells and the NaCl solutions is zero.
B. At X, Na and Cl ions disrupt the structure of cell membranes.
C. At Y, the hypertonic NaCl solutions diffuse into the red blood cells.
D. At X, water has moved by osmosis into the red blood cells.
[1]
D
This question performed well in terms in terms of difficulty and in having a high discrimination index on the paper.
