Question 22M.2.HL.TZ2.a.ii
| Date | May 2022 | Marks available | [Maximum mark: 1] | Reference code | 22M.2.HL.TZ2.a.ii |
| Level | HL | Paper | 2 | Time zone | TZ2 |
| Command term | Calculate | Question number | a.ii | Adapted from | N/A |
The onion (Allium cepa) root cells shown in the micrograph are in different stages of mitosis.
[Source: Reischig, J., 2014. Mitosis (261 13) [Pressed; root meristem of onion]. [image online] Available at https://commons.wikimedia.org/wiki/File:Mitosis_(261_13)_Pressed;_root_meristem_of_onion_(cells_in_prophase,_metaphase,_anaphase,_telophase).jpg This file is licensed under the Creative Commons Attribution -ShareAlike 3.0 Unported (CC BY-SA 3.0) https://creativecommons.org/licenses/by-sa/3.0/deed.en [Accessed 3 December 2019].]
_Pressed;_root_meristem_of_onion_(cells_in_prophase,_metaphase,_anaphase,_telophase).jpg){kind=link}
Calculate the length of the entire cell labelled Y, showing your working.
[1]
50 μm = 27/28/29 mm, Y = 8/9/10 mm
OR
50 x 9 /27
OR
16.7 μm (accept answers in the range of 14.8 μm to 17.2 μm)
Award [1] for correct ratios not precise measurements in the work or [1] for correct answer with correct unit.
Most answers were correct, but some calculations were difficult to follow; some errors in unit conversions led to incorrect decimal places.
