DP Biology (first assessment 2025)
Question 19N.2.SL.TZ0.6b
| Date | November 2019 | Marks available | [Maximum mark: 4] | Reference code | 19N.2.SL.TZ0.6b |
| Level | SL | Paper | 2 | Time zone | TZ0 |
| Command term | Outline | Question number | b | Adapted from | N/A |
b.
[Maximum mark: 4]
19N.2.SL.TZ0.6b
(b)
Outline how two parents could have a child with any of the four ABO blood groups.
[4]
Markscheme
a. «first set of» gametes/parental genotype IA, i ✔
b. «other set of» gametes/parental genotype IB, i ✔
c. «genotypes of offspring are respectively» IAIB, IBi, IAi, ii ✔ All four correct required.
d. «phenotypes of offspring are respectively» AB, B, A, O ✔ All four correct required linked to genotypes
Award marks only for the first grid if more than one drawn;
e.g. of Punnett grid
Answers can be given in a Punnett grid or in prose.
Accept the four possible blood groups of the offspring anywhere in the answer.
