PEAZIT Aha card
Go straight to resources ↓Meiosis: reduce two sets to one
DNA is copied once before meiosis, followed by two divisions. The first separates homologous chromosomes; the second separates sister chromatids. A diploid nucleus produces haploid products.
| Observation | What it means |
|---|---|
| Meiosis I | homologous chromosomes separate |
| Meiosis II | sister chromatids separate |
One worked example
- Model 2n = 6There are three homologous pairs.
- After division I: n = 3Each chromosome still has two chromatids.
- After division II: n = 3Each chromosome now has one chromatid.
Watch out: Four haploid nuclear products form, but egg formation does not produce four equally sized functional gametes.
Goal, prerequisites and card origin
What you will learn: Explain the reduction in chromosome sets.
What you need first: Mitosis and chromosome pairs.
An original PEAZIT working card. Independent expert review and effectiveness testing have not yet taken place. · v1
Reference for the underlying principle ↗Show connections
DNA is copied once before meiosis, followed by two divisions. The first separates homologous chromosomes; the second separates sister chromatids. A diploid nucleus produces haploid products.