Question 23M.2.SL.TZ2.3
| Date | May 2023 | Marks available | [Maximum mark: 4] | Reference code | 23M.2.SL.TZ2.3 |
| Level | SL | Paper | 2 | Time zone | TZ2 |
| Command term | Predict, State, Suggest | Question number | 3 | Adapted from | N/A |
The light micrograph shows tumour tissue from a patient’s lung.
[Source: Nephron, 2012. Lung carcinoid – very high mag. [image online] Available at: https://commons.wikimedia.org/wiki/
File:Lung_carcinoid_-_very_high_mag.jpg [Accessed 18 October 2021]. Public domain.]
State one cause of lung cancer.
[1]
- smoking/tobacco;
- passive smoking;
- Radon/other radiation;
- exposure to arsenic/asbestos/smoke from coal burning/fires/silica/rock dust/vehicle exhaust fumes/nitrogen oxides;
Almost every candidate could state that smoking was a cause of lung cancer. Candidates should be careful of giving more than one cause, as only the first answer is accepted in questions like this.
Suggest one difference between tissue taken from a lung cancer tumour and normal lung tissue that might be seen in micrographs.
[1]
- fewer/smaller/lack of alveoli/air spaces;
- many cells/nuclei per area / much denser tissue;
- more cells undergoing mitosis (in the tumour);
A reference to fewer air spaces, or more cells was looked for.
The lung tumour in the light micrograph was slow-growing. Predict with a reason what would have been visible in the micrograph if the tumour was growing rapidly.
[2]
See
a. more mitosis
OR
cells in prophase/metaphase/anaphase/telophase;
Why
b. more dividing cells/tumour cell divide uncontrollably
OR
a higher mitotic index;
A reference to a greater mitotic index/more mitosis was looked for. Many tried to answer in terms of emphysema, saying that there would be more air spaces.
