Cambridge O Level Biology · Syllabus 5090 · Development of Organisms and Continuity of Life
Sexual Reproduction
What is Sexual Reproduction?
A process involving the fusion of the nuclei of two gametes to form a zygote, and the production of offspring that are genetically different from each other. The gametes are haploid and are made by meiosis, so the zygote is diploid.
This definition is part of the Development of Organisms and Continuity of Life chapter in Cambridge O Level Biology.
Common mistakes with Sexual Reproduction
- “Sexual reproduction guarantees that the offspring survive environmental change.” Why wrong Variation is not insurance. Most offspring may still die; what changes is the chance that some are suited to the new conditions. Say instead Variation increases the probability that some individuals survive a change, so the population is more likely to persist.
- “Self-pollination is asexual reproduction.” Why wrong Gametes are still made by meiosis and two haploid nuclei still fuse. That is sexual reproduction, regardless of where the pollen came from. Say instead Self-pollination is sexual reproduction with less genetic variation than cross-pollination.
Last reviewed Syllabus 2026-2028