Science
What is Meiosis?
Meiosis is a special type of cell division that makes sex cells — eggs and sperm — each with half the normal number of chromosomes. It also shuffles genes, which is why offspring differ from their parents and from each other.
See it, don’t just read it.
Watch a 2-minute lesson with voice + animation that explains meiosis.
Key things to understand
- 1It halves the chromosome count, so fertilization can restore the full set.
- 2One cell divides twice to produce four genetically unique cells.
- 3Genes are reshuffled ('crossing over'), creating variation.
- 4It is essential for sexual reproduction and inheritance.
- 5Errors can cause conditions linked to extra or missing chromosomes.
Frequently asked questions
- How is meiosis different from mitosis?
- Mitosis copies a cell into two identical cells; meiosis makes four genetically varied sex cells with half the chromosomes.
- Why does meiosis create variation?
- It mixes the parents' genes through crossing over and random sorting, so each egg or sperm carries a unique combination.
- Why must sex cells have half the chromosomes?
- So that when egg and sperm combine, the offspring ends up with the correct full number, not double.