In the first stage of reproduction what disappears?

In the context of cellular reproduction (e.g., mitosis or meiosis), the nuclear membrane disappears during the first stage of active division, known as prophase.

Here’s what happens:

1. Chromosomes condense and become visible.
2. The nuclear membrane breaks down, allowing the chromosomes to interact with the spindle fibers.
3. The spindle apparatus forms, preparing the cell for the separation of genetic material.

This process is crucial for ensuring that genetic information is distributed accurately to the daughter cells.