Reproduction
Reproduction is the processes that make more of the same kind of organism 1. It is the one life process that is not needed by the individual organism itself — it is needed by the species.
Asexual and Sexual Reproduction
| Feature | Asexual | Sexual |
|---|---|---|
| Parents | One | Two (usually) |
| Gametes | None | Two gamete nuclei fuse |
| Offspring | Genetically identical to the parent | Genetically different from each other |
| Speed and numbers | Fast, many offspring from one parent | Slower, fewer offspring |
| Variation | None added | New combinations of alleles |
Fertilisation is the fusion of the nuclei of gametes, forming a zygote. Gamete nuclei are haploid and the zygote nucleus is diploid, so the chromosome number is restored at fertilisation.
haploid sperm nucleus ─┐
├─► diploid zygote ─► new organism
haploid egg nucleus ─┘Variation and the Species
Because sexual reproduction reshuffles alleles, the offspring differ from one another — raw material for natural selection. A lack of variation in asexual offspring means a whole population can share one vulnerability. The syllabus defines a species as a group of organisms that can reproduce to produce fertile offspring 1.
Related
- Living Thing - Entity carrying out all seven life processes.
- Organism - Individual living thing, unicellular or multicellular.
- Growth - Mitosis underlies growth and asexual reproduction alike.
- Nucleus - Gamete nuclei fuse at fertilisation.
- Nutrition - Materials for the gametes and offspring produced.
- Biology - Cambridge IGCSE life-science area.
Footnotes
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Cambridge IGCSE Biology 0610 syllabus for examination in 2026, 2027 and 2028 - Reproduction (1.1e), species definition (1.2.2), gametes as specialised cells (2.1.6), asexual and sexual reproduction (16.1-16.2), mitosis and asexual reproduction (17.2). ↩ ↩2