Replicate Once, Divide Twice

You'll learnwhere meiosis halves the chromosome number, and how counting centromeres settles it.

One diploid cell goes in and four gametes come out, each carrying half the chromosomes. The halving happens in exactly one place, and if you count the right object — the centromere — you can watch it happen. Eleven short steps; press Next for each one.

AP BIOLOGY · 11 STEPS · 6 QUICK CHECKS · 2n = 4 → n = 2 · MEIOSIS I HALVES IT · v5

2n = 4 · count the ringed centromeres · one halving, at meiosis I

Before you start

What you're looking at

A diploid parent cell with two pairs of chromosomes, one from each parent in each pair, every chromosome marked by a ringed centromere.

The question

Where in meiosis does the chromosome number actually get halved?

Step 1 / 11