The number of organelles doubles. Chromosomes must be copied. Four nuclei must be formed. The membrane thickens.
I am hesitating between 4 options to answer the following question, which option should I choose?
Question: At the end of the mitotic cell cycle, a cell divides into two cells. What must happen before the cell divides?
Possibilities:
- The number of organelles doubles.
- Chromosomes must be copied.
- Four nuclei must be formed.
- The membrane thickens.

Chromosomes must be copied.