What happens during prophase 1 of meiosis?

Chromosomes become visible, crossing-over occurs, the nucleolus disappears, the meiotic spindle forms, and the nuclear envelope disappears. To see prophase I animated, click the Play button. animation. Play ▷. Reset ↺. At the start of prophase I, the chromosomes have already duplicated. read more

During this phase of meiosis, chromosomes become visible, crossing-over occurs, the nucleolus disappears, the meiotic spindle forms, and the nuclear envelope disappears. * At the start of prophase I, the chromosomes have already duplicated. read more

At the start of prophase I, the chromosomes have already duplicated. During prophase I, they coil and become shorter and thicker and visible under the light microscope. The duplicated homologous chromosomes pair, and crossing-over (the physical exchange of chromosome parts) occurs. read more