Labs / Biology
Meiosis & Crossing Over
A pair of homologous chromosomes has replicated and lined up. Green segments came from one parent, orange from the other. Grab a crossover knob between the two inner chromatids and slide it — then watch the cell divide twice into four gametes, each with its own mix of alleles.
types 2/4crossovers 1recomb 2/4
What to try
- With no crossover, how many genetically different gametes can one cell make?
- Add a single crossover and drag it. Which alleles end up swapped, and which two gametes become recombinant?
- Set a double crossover and slide the two knobs close together. Why can a second crossover undo the first?
- Flip "Alt. assortment" without touching the crossovers. How can gametes change when no segments were swapped?
- What combination of crossovers and assortment produces four completely different gametes?