O-LevelBiologyGenetics & Variation5090/12 · Oct/Nov 2021 · Q401 Mark

During the division of a nucleus by meiosis, changes can happen that produce a gamete with an abnormal number of genes or chromosomes. Which change might produce a gamete that can result in a child having Down's syndrome?

Agamete with one extra chromosome

Bgamete that lacks one gene

Cgamete that lacks one chromosome

Dgamete with one extra gene

✓ Correct answer

A: gamete with one extra chromosome

Oracle Prep sorts past-paper questions by topic, so you can drill Genetics & Variation and see which topics are most likely to come up next.

Topic: Genetics & Variation, O-Level Biology (syllabus 5090). Multiple choice, 1 mark.
Source: O-Level Biology, Oct/Nov 2021 Paper 1 Variant 2, question 40.

Questions and mark schemes are from past examination papers and remain the copyright of the exam board. How Oracle Prep builds its content