DP Biology (last assessment 2024)
Question 18N.3.SL.TZ0.3
| Date | November 2018 | Marks available | [Maximum mark: 3] | Reference code | 18N.3.SL.TZ0.3 |
| Level | SL | Paper | 3 | Time zone | TZ0 |
| Command term | Calculate, Deduce | Question number | 3 | Adapted from | N/A |
3.
[Maximum mark: 3]
18N.3.SL.TZ0.3
The micrograph shows mitosis in a cell of an onion (Allium cepa) root tip.
(a)
Deduce, with a reason, which stage of mitosis is shown.
[2]
Markscheme
a. telophase ✔
b. chromatids/chromosomes have been pulled to the poles of the cell
OR
«2» new/daughter nuclei forming ✔
Do not accept cytokinesis
(b)
The cells visible in the onion root tip were classified and counted.
Calculate the mitotic index.
[1]
Markscheme
0.3 or 30 % ✔
