Meiosis Lab

Simplified model. Pair 1 carries two linked genes (A near one end, B near the other); every other pair carries one gene. When crossing over is on, every pair gets one crossover at a random point, as most real pairs get at least one. Which homolog faces which pole at metaphase I, and which sister chromatid goes up in meiosis II, are random (50:50). The partner's gamete is always normal (n). Speeds are exaggerated.

Problems are generated at random. The picture shows the cell or numbers in the problem; the worked solution builds step by step underneath, with a common-mistake note. For "predict, then watch" problems, the bench animation plays the answer once you have chosen.