DP Biology (last assessment 2024)
Question 19M.2.HL.TZ1.c.ii
| Date | May 2019 | Marks available | [Maximum mark: 1] | Reference code | 19M.2.HL.TZ1.c.ii |
| Level | HL | Paper | 2 | Time zone | TZ1 |
| Command term | State | Question number | c.ii | Adapted from | N/A |
c.ii.
[Maximum mark: 1]
19M.2.HL.TZ1.c.ii
The karyogram shown is for the African marsh rat (Dasymys incomtus). In this species, sex is determined by X and Y chromosomes. Females are XX and males are XY.
[Source: adapted from https://embryology.med.unsw.edu.au]
State the haploid number for this nucleus.
[1]
Markscheme
21
Examiners report
Slightly more than 50 % of candidates got this right. A common wrong answer was 42 – diploid number. There were a variety of other answers, some of which must have been guesses from candidates who did not understand the term haploid.
