Mitosis vs Meiosis: Two Divisions, Two Outcomes
Mitosis and meiosis sound similar but serve completely different purposes. Master the four key differences (cell count, ploidy, purpose, genetic identity) and you'll never miss a comparison question.
Why this is one of the most-missed comparisons
Mitosis and meiosis both divide cells. They use similar-looking diagrams, similar phase names, and similar terminology. That’s exactly why students mix them up — and why the CBE writes at least one direct comparison question per exam.
The good news: there are only four key differences. Memorize this table and you’ll never miss it.
The four differences that matter
| Feature | Mitosis | Meiosis |
|---|---|---|
| Daughter cells | 2 | 4 |
| Ploidy | Diploid (2n) | Haploid (n) |
| Genetic identity | Identical to parent | Genetically unique |
| Purpose | Growth, repair, asexual reproduction | Sexual reproduction (makes gametes) |
Visual side-by-side
What “diploid” and “haploid” really mean
Humans have 46 chromosomes — that’s the diploid number (2n = 46). Meiosis cuts that in half to 23 — that’s the haploid number (n = 23). When a sperm (n=23) fertilizes an egg (n=23), the resulting zygote is back to 2n=46.
- Diploid (2n) — full set of chromosomes, in homologous pairs.
- Haploid (n) — half set, one of each pair. Only sperm and eggs are haploid.
When does each one happen?
- Mitosis: every cell in your body except sperm/egg cells. Skin, bone, muscle, intestine — they all divide by mitosis to grow and repair.
- Meiosis: only in germ cells (testes and ovaries) to produce sperm and eggs.
Crossing over: meiosis-only
One unique feature of meiosis: during prophase I, homologous chromosomes swap segments — this is crossing over. It’s why meiosis daughter cells are genetically different from each other (and from the parent). Mitosis has no crossing over, so its daughter cells are clones.