Final answer:
Meiosis I is the stage of meiosis where the main differences from mitosis occur. Homologous chromosomes physically meet, chiasmata form, and crossover occurs between nonsister chromatids.
Step-by-step explanation:
The main differences between meiosis and mitosis occur in meiosis I. Meiosis I is the stage of meiosis where the main differences from mitosis occur. Homologous chromosomes physically meet, chiasmata form, and crossover occurs between nonsister chromatids.
In meiosis I, the homologous chromosome pairs physically meet and are bound together with the synaptonemal complex.
Following this, the chromosomes develop chiasmata and undergo crossover between nonsister chromatids. In the end, the chromosomes line up along the metaphase plate as tetrads, with kinetochore fibers from opposite spindle poles attached to each kinetochore of a homolog to form a tetrad. All of these events occur only in meiosis I.